Taurus efan manual switch causing electrical problems
08-03-13, 04:04 PM
#1
Taurus efan manual switch causing electrical problems
Here's the story. I've got a Taurus efan wired in with a 40a 5-pin relay with a Starion temp switch located on the back of the water pump housing. Here is the wiring diagram I used for wiring it in.
12v IGN is coming off the 6pin check connector by the battery. I recently had a short in that wire. I routed the wire under the battery tray. I did not know the wire was pinched and eventually the insulation wore away and created a short.
Oh and I have not tied in the idle up via 1O at the ECU. And the manual switch is wired into the interior, grounded at the driver side kick panel.
In trying to find that short I got cute and long story short, I melted the wiring insulation from the short under the battery, to the 6 pin check connector, to the main relay and to the EGI fuse. I replaced all that wiring as well as the main relay just to be sure. The only wiring I did not replace was the B/W wiring running from the main relay to the 6 pin and single pin green connectors. I saw that wiring was also routed to a relay under the dash on passenger side as well as an airbag connector or relay (can't remember which at the moment). IIRC it then goes to the ECU. I checked all that wiring on the interior and didn't see any signs of damage to the insulation in the interior of the car so I opted to simply splice into that B/W wire at the point where the two green connectors join and at the main relay connector.
Everything works fine, until my fan has been running with the manual switch turned on for a extended period of time. Then it starts running very rough, RPMs drop 1k-1500 spontaneously and if I let my foot off the gas it will stall. It happened today in stop and go traffic and I barely got the car into a parking lot.
I looked over the wiring and fuses in the parking lot and didn't see any visual signs. After the car sat for 5-10 minutes I turned the engine over, everything was running fine and I moved it to a better parking spot...and there it sits. I'm waiting for the engine to cool down and I'll go back for the car. It's close enough to home that once the sun goes down and the engine cools I can get it home before the fan comes on.
It drives fine until the efan switches on and has been running for some time. Any suggestions on where I should start testing and checking? I'll start with the efan relay, is it possible that the relay was damaged when the wiring was? Other than having 12v IGN tied into that 6 pin connector the efan wiring it isn't tied into any other electrical for the engine, so I'm thinking that's a long shot. Maybe the alternator?
12v IGN is coming off the 6pin check connector by the battery. I recently had a short in that wire. I routed the wire under the battery tray. I did not know the wire was pinched and eventually the insulation wore away and created a short.
Oh and I have not tied in the idle up via 1O at the ECU. And the manual switch is wired into the interior, grounded at the driver side kick panel.
In trying to find that short I got cute and long story short, I melted the wiring insulation from the short under the battery, to the 6 pin check connector, to the main relay and to the EGI fuse. I replaced all that wiring as well as the main relay just to be sure. The only wiring I did not replace was the B/W wiring running from the main relay to the 6 pin and single pin green connectors. I saw that wiring was also routed to a relay under the dash on passenger side as well as an airbag connector or relay (can't remember which at the moment). IIRC it then goes to the ECU. I checked all that wiring on the interior and didn't see any signs of damage to the insulation in the interior of the car so I opted to simply splice into that B/W wire at the point where the two green connectors join and at the main relay connector.
Everything works fine, until my fan has been running with the manual switch turned on for a extended period of time. Then it starts running very rough, RPMs drop 1k-1500 spontaneously and if I let my foot off the gas it will stall. It happened today in stop and go traffic and I barely got the car into a parking lot.
I looked over the wiring and fuses in the parking lot and didn't see any visual signs. After the car sat for 5-10 minutes I turned the engine over, everything was running fine and I moved it to a better parking spot...and there it sits. I'm waiting for the engine to cool down and I'll go back for the car. It's close enough to home that once the sun goes down and the engine cools I can get it home before the fan comes on.
It drives fine until the efan switches on and has been running for some time. Any suggestions on where I should start testing and checking? I'll start with the efan relay, is it possible that the relay was damaged when the wiring was? Other than having 12v IGN tied into that 6 pin connector the efan wiring it isn't tied into any other electrical for the engine, so I'm thinking that's a long shot. Maybe the alternator?
08-03-13, 08:22 PM
#4
Did you use this setup before the wiring replacement?
Check your voltage at the battery with the fan off and then with the fan on. If it drops, the fan is pulling too much current for the alt.
Re-wrapped alts don't improve lower rpm output much, so how you drive it can affect how well it charges. Stop and go being basically a worst case scenario.
Check your voltage at the battery with the fan off and then with the fan on. If it drops, the fan is pulling too much current for the alt.
Re-wrapped alts don't improve lower rpm output much, so how you drive it can affect how well it charges. Stop and go being basically a worst case scenario.
08-03-13, 08:38 PM
#5
Definitely sounds like your alternator is not up to scratch, a voltage check with the fan off, then on will confirm how well the alternator is keeping up. Something to keep in mind is that the 2-speed Taurus Fan is VERY thirsty and draws a consistent 30 amps on high. IIRC, low speed's current draw is somewhere around 23 amps. Also, the times in which the fan would normally be used are when in neutral or cruising slowly, times when the alternator isn't putting out much power (worst case scenario).
Even with a 100A FD alternator, the Taurus fan was just pulling too much juice on my car. A 130A Taurus Alternator does the job quite nicely and will keep things floating when the fan comes on. Since mine was getting kinda funky in the voltage regulator due to age, I picked up another taurus alt at the junkyard on half price day for $10.
FWIW, your wiring diagram looks perfectly sound and well thought out with the manual override switch wired in parallel to the thermoswitch. The only nitpick I can draw is that the relay would be utilized better on the fan's 12v wire instead of the ground. This would enable using both low speed as you have it now and high speed in whatever manner you choose (second thermoswitch, A/C triggered, manual switch, etc).
Even with a 100A FD alternator, the Taurus fan was just pulling too much juice on my car. A 130A Taurus Alternator does the job quite nicely and will keep things floating when the fan comes on. Since mine was getting kinda funky in the voltage regulator due to age, I picked up another taurus alt at the junkyard on half price day for $10.
FWIW, your wiring diagram looks perfectly sound and well thought out with the manual override switch wired in parallel to the thermoswitch. The only nitpick I can draw is that the relay would be utilized better on the fan's 12v wire instead of the ground. This would enable using both low speed as you have it now and high speed in whatever manner you choose (second thermoswitch, A/C triggered, manual switch, etc).
08-03-13, 09:39 PM
#7
Did you use this setup before the wiring replacement?
Check your voltage at the battery with the fan off and then with the fan on. If it drops, the fan is pulling too much current for the alt.
Re-wrapped alts don't improve lower rpm output much, so how you drive it can affect how well it charges. Stop and go being basically a worst case scenario.
Check your voltage at the battery with the fan off and then with the fan on. If it drops, the fan is pulling too much current for the alt.
Re-wrapped alts don't improve lower rpm output much, so how you drive it can affect how well it charges. Stop and go being basically a worst case scenario.
Definitely sounds like your alternator is not up to scratch, a voltage check with the fan off, then on will confirm how well the alternator is keeping up. Something to keep in mind is that the 2-speed Taurus Fan is VERY thirsty and draws a consistent 30 amps on high. IIRC, low speed's current draw is somewhere around 23 amps. Also, the times in which the fan would normally be used are when in neutral or cruising slowly, times when the alternator isn't putting out much power (worst case scenario).
Even with a 100A FD alternator, the Taurus fan was just pulling too much juice on my car. A 130A Taurus Alternator does the job quite nicely and will keep things floating when the fan comes on. Since mine was getting kinda funky in the voltage regulator due to age, I picked up another taurus alt at the junkyard on half price day for $10.
FWIW, your wiring diagram looks perfectly sound and well thought out with the manual override switch wired in parallel to the thermoswitch. The only nitpick I can draw is that the relay would be utilized better on the fan's 12v wire instead of the ground. This would enable using both low speed as you have it now and high speed in whatever manner you choose (second thermoswitch, A/C triggered, manual switch, etc).
Even with a 100A FD alternator, the Taurus fan was just pulling too much juice on my car. A 130A Taurus Alternator does the job quite nicely and will keep things floating when the fan comes on. Since mine was getting kinda funky in the voltage regulator due to age, I picked up another taurus alt at the junkyard on half price day for $10.
FWIW, your wiring diagram looks perfectly sound and well thought out with the manual override switch wired in parallel to the thermoswitch. The only nitpick I can draw is that the relay would be utilized better on the fan's 12v wire instead of the ground. This would enable using both low speed as you have it now and high speed in whatever manner you choose (second thermoswitch, A/C triggered, manual switch, etc).
As far as the the modded alt being up to task, I've used the same alternator before needing to replace wiring with no issues like this. It was previously up to the task, but who knows...a modded alternator may not have a long lifespan?
I wish I could do a Taurus alt, unfortunately I've got the TMIC and that thing will never fit under it. I know the downside of modded alts and low RPM. I can watch my OEM volt meter rise from idle RPM to higher levels. I make a habit of keeping the RPMs up a little at lights when the fan is running.
About the relay and wiring, I'm actually considering going with a Volvo two speed relay and thermoswitch. I picked up the relay last time I was at the junkyard. I haven't been all that happy with the Starion, IIRC it should be a 195 on switch, but doesnt' come on till 205-210...well if my Prosport temp gauge is accurate. I may start doing some research on whether I can re-tap my water pump housing for the Volvo switch....as I remember it the Volvo switch's probe is pretty flat...I don't know how well it would work there.
I also thought of the motor on the fan itself, but don't have the tools to test it beyond jumpering it to see if it spins on high and low.
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08-05-13, 09:33 AM
#10
08-05-13, 07:54 PM
#11
Did you use this setup before the wiring replacement?
Check your voltage at the battery with the fan off and then with the fan on. If it drops, the fan is pulling too much current for the alt.
Re-wrapped alts don't improve lower rpm output much, so how you drive it can affect how well it charges. Stop and go being basically a worst case scenario.
Check your voltage at the battery with the fan off and then with the fan on. If it drops, the fan is pulling too much current for the alt.
Re-wrapped alts don't improve lower rpm output much, so how you drive it can affect how well it charges. Stop and go being basically a worst case scenario.
08-08-13, 05:32 PM
#12
I thought I had it sorted out. I checked voltage with the fan on and off. It's exactly how you'd expect from a modded alternator. Low RPM the alternator can't keep up but if I hold it between 1k-1500 rpms I get a solid high 13-14v.
I thought I had it all sorted out. I had a short day at work earlier this week and was going to put some miles on the car...only too find a drained battery just a couple days after doing my test.
The last time I ran into this problem with the engine wanting to stall out, I later go out to start the engine up and do some tests...to find a drained battery. I charged it and looked for a parasitic drain and the DMM showed around 30-40mA. From what I had read thats within tolerances.
Now it's back to low voltage on the battery. I checked battery voltage this morning before work and I only had 5.8ish volts. I checked again when I got off of work and it was down to 4.8ish. Apparently I have a sporadic parasitic drain. I'll get the battery charged up again and check again for a drain on the battery.
What are the possibilities of it being the fan motor? I pull the battery to charge it and doing that cuts the current draw. So when I test for a parasitic drain after putting the battery back in I don't see it. The parasitic drain doesn't return till the fan motor has been switched on...and the draw continues after the motor as stopped? Is that a possibility?
I thought I had it all sorted out. I had a short day at work earlier this week and was going to put some miles on the car...only too find a drained battery just a couple days after doing my test.
The last time I ran into this problem with the engine wanting to stall out, I later go out to start the engine up and do some tests...to find a drained battery. I charged it and looked for a parasitic drain and the DMM showed around 30-40mA. From what I had read thats within tolerances.
Now it's back to low voltage on the battery. I checked battery voltage this morning before work and I only had 5.8ish volts. I checked again when I got off of work and it was down to 4.8ish. Apparently I have a sporadic parasitic drain. I'll get the battery charged up again and check again for a drain on the battery.
What are the possibilities of it being the fan motor? I pull the battery to charge it and doing that cuts the current draw. So when I test for a parasitic drain after putting the battery back in I don't see it. The parasitic drain doesn't return till the fan motor has been switched on...and the draw continues after the motor as stopped? Is that a possibility?
08-09-13, 01:52 PM
#13
I thought I had it sorted out. I checked voltage with the fan on and off. It's exactly how you'd expect from a modded alternator. Low RPM the alternator can't keep up but if I hold it between 1k-1500 rpms I get a solid high 13-14v.
I thought I had it all sorted out. I had a short day at work earlier this week and was going to put some miles on the car...only too find a drained battery just a couple days after doing my test.
The last time I ran into this problem with the engine wanting to stall out, I later go out to start the engine up and do some tests...to find a drained battery. I charged it and looked for a parasitic drain and the DMM showed around 30-40mA. From what I had read thats within tolerances.
Now it's back to low voltage on the battery. I checked battery voltage this morning before work and I only had 5.8ish volts. I checked again when I got off of work and it was down to 4.8ish. Apparently I have a sporadic parasitic drain. I'll get the battery charged up again and check again for a drain on the battery.
What are the possibilities of it being the fan motor? I pull the battery to charge it and doing that cuts the current draw. So when I test for a parasitic drain after putting the battery back in I don't see it. The parasitic drain doesn't return till the fan motor has been switched on...and the draw continues after the motor as stopped? Is that a possibility?
I thought I had it all sorted out. I had a short day at work earlier this week and was going to put some miles on the car...only too find a drained battery just a couple days after doing my test.
The last time I ran into this problem with the engine wanting to stall out, I later go out to start the engine up and do some tests...to find a drained battery. I charged it and looked for a parasitic drain and the DMM showed around 30-40mA. From what I had read thats within tolerances.
Now it's back to low voltage on the battery. I checked battery voltage this morning before work and I only had 5.8ish volts. I checked again when I got off of work and it was down to 4.8ish. Apparently I have a sporadic parasitic drain. I'll get the battery charged up again and check again for a drain on the battery.
What are the possibilities of it being the fan motor? I pull the battery to charge it and doing that cuts the current draw. So when I test for a parasitic drain after putting the battery back in I don't see it. The parasitic drain doesn't return till the fan motor has been switched on...and the draw continues after the motor as stopped? Is that a possibility?
I've never personally seen a battery pulled down that far, but I would suspect the battery is bad now. When my previous battery (from Autozone) would only put out 7.2v when cranking, despite showing 12.3v at rest after being fully charged, I knew it was shot from being drained quite a few times due to a weak, insufficient S4 alternator in its early days. A good battery will read 10.0v or better when cranking our engines.
Called up Remy Battery and ordered a Deka Intimidator 9A48. As for replacing the alternator, I'm just going to reiterate what has been said before. A 130A Taurus Alternator won't disappoint you if wired properly. After use in the donor car, then my RX7, my Taurus Alternator finally started acting up last week. It wasn't the windings/diodes/power generating stuff, but the voltage regulator that gave out and was trying to overcharge to the point where it tripped the 150A breaker next to the rear mounted battery. A new F0DF regulator (93 Taurus 3.8L) could have been found for $15 on ebay, but I just decided to get another alternator at the junkyard on half price day for $10 from a 94 Windstar 3.8L. Regulator is slightly different (is a 'smart' Load Response Controller type regulator), but everything else is the same. Puts put a solid 13-14v everywhere on the tachometer.
Wiring:
BTW, if you give the Taurus Alt constant 12v on the green wire in place of Ignition-switched 12v, it will drain the battery. This is why Project OldTree has a dedicated relay & two-stud bus bar for devices needing ignition-switched 12v
08-10-13, 08:31 AM
#14
No, the fan cannot be draining your battery unless the relay is sticking in the ON position. This is why I suggested having the relay on the fan's power wire instead of its ground.
I've never personally seen a battery pulled down that far, but I would suspect the battery is bad now. When my previous battery (from Autozone) would only put out 7.2v when cranking, despite showing 12.3v at rest after being fully charged, I knew it was shot from being drained quite a few times due to a weak, insufficient S4 alternator in its early days. A good battery will read 10.0v or better when cranking our engines.
Called up Remy Battery and ordered a Deka Intimidator 9A48. As for replacing the alternator, I'm just going to reiterate what has been said before. A 130A Taurus Alternator won't disappoint you if wired properly. After use in the donor car, then my RX7, my Taurus Alternator finally started acting up last week. It wasn't the windings/diodes/power generating stuff, but the voltage regulator that gave out and was trying to overcharge to the point where it tripped the 150A breaker next to the rear mounted battery. A new F0DF regulator (93 Taurus 3.8L) could have been found for $15 on ebay, but I just decided to get another alternator at the junkyard on half price day for $10 from a 94 Windstar 3.8L. Regulator is slightly different (is a 'smart' Load Response Controller type regulator), but everything else is the same. Puts put a solid 13-14v everywhere on the tachometer.
Wiring:
BTW, if you give the Taurus Alt constant 12v on the green wire in place of Ignition-switched 12v, it will drain the battery. This is why Project OldTree has a dedicated relay & two-stud bus bar for devices needing ignition-switched 12v
I've never personally seen a battery pulled down that far, but I would suspect the battery is bad now. When my previous battery (from Autozone) would only put out 7.2v when cranking, despite showing 12.3v at rest after being fully charged, I knew it was shot from being drained quite a few times due to a weak, insufficient S4 alternator in its early days. A good battery will read 10.0v or better when cranking our engines.
Called up Remy Battery and ordered a Deka Intimidator 9A48. As for replacing the alternator, I'm just going to reiterate what has been said before. A 130A Taurus Alternator won't disappoint you if wired properly. After use in the donor car, then my RX7, my Taurus Alternator finally started acting up last week. It wasn't the windings/diodes/power generating stuff, but the voltage regulator that gave out and was trying to overcharge to the point where it tripped the 150A breaker next to the rear mounted battery. A new F0DF regulator (93 Taurus 3.8L) could have been found for $15 on ebay, but I just decided to get another alternator at the junkyard on half price day for $10 from a 94 Windstar 3.8L. Regulator is slightly different (is a 'smart' Load Response Controller type regulator), but everything else is the same. Puts put a solid 13-14v everywhere on the tachometer.
Wiring:
BTW, if you give the Taurus Alt constant 12v on the green wire in place of Ignition-switched 12v, it will drain the battery. This is why Project OldTree has a dedicated relay & two-stud bus bar for devices needing ignition-switched 12v
For the battery, I'm using an Optima red top that's still under warranty. I had it charging overnight and in the AM my DMM showed it was at 15v and when I took it off the charger it was hissing. I let it sit while I was at work. When I got home I checked voltage and it's sitting at 12.7ish. A friend manages the Advanced Auto where I bought it, I'm gonna take it to him once his shift starts and let him test it.
If I make any changes to the fan wiring I'll probably go with the Volvo 2 speed relay setup. Last time I was at the junkyard I picked up a relay. I need to do a little research and find out the pitch and thread of the Volvo temp switch, see if I could tap that into my OEM spot on the back of the turbo water pump housing.
08-12-13, 05:52 AM
#15
The engine is still having troubles, but I believe I've narrowed it down. I think my alternator is sporadically failing. Took the car for a drive yesterday and everything was fine till the fan came on and I stopped the car. About the time the engine got to temps where the fan was needed I got to a coffee shop. The engine sat for about an hour before I moved on. When I first turned the engine over the OEM volt meter was flat on 12v. Bumping up the RPM at first did nothing. It wasn't until I was some ways down the road that the volt meter started showing readings above 12v. Then when the fan needed to trigger on I knew it was coming. The engine started sputtering and such.
I eventually got the car home but I had to sit with it till the engine cooled enough that the fan didn't need to turn on.
Seems that the alternator is failing.
Oh and the battery tested as fine
I eventually got the car home but I had to sit with it till the engine cooled enough that the fan didn't need to turn on.
Seems that the alternator is failing.
Oh and the battery tested as fine
08-12-13, 06:21 PM
#16
I seem to recall a few reports of some guys with stock TMICs being able to fit a Taurus Alternator without too much difficulty. It will take extending the output post and clocking it at roughly 1-2 o'clock to have enough space for the cable lug & a rubber boot.
https://www.rx7club.com/2nd-generati...-785082/page8/
Afpreppie04 has uploaded a picture of a Taurus Alternator fitting under the stock TMIC in post #177. Says it's a tight fit, but it can be done. Having an electrically-sound car says it's worth spending a couple hours with a drill, die grinder and some hardware store steel to make perfectly spaced adapter brackets.
https://www.rx7club.com/2nd-generati...-785082/page8/
Afpreppie04 has uploaded a picture of a Taurus Alternator fitting under the stock TMIC in post #177. Says it's a tight fit, but it can be done. Having an electrically-sound car says it's worth spending a couple hours with a drill, die grinder and some hardware store steel to make perfectly spaced adapter brackets.
08-12-13, 07:22 PM
#17
I seem to recall a few reports of some guys with stock TMICs being able to fit a Taurus Alternator without too much difficulty. It will take extending the output post and clocking it at roughly 1-2 o'clock to have enough space for the cable lug & a rubber boot.
https://www.rx7club.com/2nd-generati...-785082/page8/
Afpreppie04 has uploaded a picture of a Taurus Alternator fitting under the stock TMIC in post #177. Says it's a tight fit, but it can be done. Having an electrically-sound car says it's worth spending a couple hours with a drill, die grinder and some hardware store steel to make perfectly spaced adapter brackets.
https://www.rx7club.com/2nd-generati...-785082/page8/
Afpreppie04 has uploaded a picture of a Taurus Alternator fitting under the stock TMIC in post #177. Says it's a tight fit, but it can be done. Having an electrically-sound car says it's worth spending a couple hours with a drill, die grinder and some hardware store steel to make perfectly spaced adapter brackets.
Your info is certainly helpful!
08-19-13, 07:52 PM
#18
I've had my alternator tested for how many amps it's pulling and it's at 128A. So the alternator appears to be good.
To recap, everything works fine until the Taurus efan kicks on. It will work fine for a while, but seems like after turning the engine off and coming back to it to drive a short time later that my OEM volt meter is showing that the battery is seeing 12v at idle, no matter if I hold RPMs up to 1500 where the modded alternator would usually kicks up to high 13 to 14v...but it doesn't. After some time the volt meter will start to climb but does it in sporadic jumps. It doesn't do the normal climb and fall.
Can it be a bad relay or bad relay and fan? Or can the alternator sporadically be failing? As in it starts failing after it's been under an extended time of load, but when I take it to be tested it doesn't see a load long enough to start acting spotty?
To recap, everything works fine until the Taurus efan kicks on. It will work fine for a while, but seems like after turning the engine off and coming back to it to drive a short time later that my OEM volt meter is showing that the battery is seeing 12v at idle, no matter if I hold RPMs up to 1500 where the modded alternator would usually kicks up to high 13 to 14v...but it doesn't. After some time the volt meter will start to climb but does it in sporadic jumps. It doesn't do the normal climb and fall.
Can it be a bad relay or bad relay and fan? Or can the alternator sporadically be failing? As in it starts failing after it's been under an extended time of load, but when I take it to be tested it doesn't see a load long enough to start acting spotty?
08-19-13, 08:00 PM
#19
What do you mean by "my OEM volt meter is showing that the battery is seeing 12v at idle." The factory gauge measures the output of the alternator and not the voltage of the battery. Are you sure your gauge is accurate. Have you tried measuring the alternator output when the gauge is giving you a poor reading?
08-19-13, 08:36 PM
#20
I went on the assumption that if the alternator is charging the battery at "x" amount that the battery and alternator are pretty close to the same reading.
I have tested it in the past solo by making long jumper wires to the driver seat. At that time the OEM gauge read the same as my DMM. And at that time the alternator was able to keep up with the Taurus fan on high, so long as I had RPMs up to 1500 or so. It would show high 13 to 14v.
I have not been able to test it yet when it's acting up. When time permits (this weekend??) my plan is to let the car idle till it's to temp for the fan to be on. Hopefully recreate the problems and then take readings.
Well, I should clarify, I had my jumper wires from the battery posts to DMM, NOT the alternator to the DMM.
I have tested it in the past solo by making long jumper wires to the driver seat. At that time the OEM gauge read the same as my DMM. And at that time the alternator was able to keep up with the Taurus fan on high, so long as I had RPMs up to 1500 or so. It would show high 13 to 14v.
I have not been able to test it yet when it's acting up. When time permits (this weekend??) my plan is to let the car idle till it's to temp for the fan to be on. Hopefully recreate the problems and then take readings.
Well, I should clarify, I had my jumper wires from the battery posts to DMM, NOT the alternator to the DMM.
08-19-13, 08:43 PM
#21
The difference between the alternator and battery can be .5 to 1 volt especially if the wiring is rather old. And I believe the voltage gauge pulls a reading from the Meter fuse. So, if the wiring from the Meter fuse to the gauge cluster is suspect that could also pose some accuracy problems.
08-25-13, 04:31 PM
#22
Finally had time to test the alternator. It's looking like the alternator can't sustain 14v over time. I ran jumper wires from battery terminals to the driver seat, attached them to my DMM and held idle between 1500-2000. I have a manual toggle switch for the fan as well as thermoswitch. At first I played around with the fan low speed and DMM was reading solid 14v. I turned the fan off and simply held idle at 1500 rpm and watched the DMM reading dropping over a period of maybe 5-10min...about the time it took the engine to get to 160 degrees on a 90 degree day. Over that time the DMM dropped to 13.7 and was continuing to drop. Maybe .01 every minute or two. That was without the fan on or any accessories on.
I probably should have let the engine idle longer to see how far the DMM would drop. I forget what the threshold voltage is for an alternator to be effectively charging the battery. IIRC it's around 13.6v? But with the DMM dropping so consistently without the fan even running I figured I'd seen all I need to see.
Opinions?
I probably should have let the engine idle longer to see how far the DMM would drop. I forget what the threshold voltage is for an alternator to be effectively charging the battery. IIRC it's around 13.6v? But with the DMM dropping so consistently without the fan even running I figured I'd seen all I need to see.
Opinions?
08-26-13, 04:08 PM
#23
Finally had time to test the alternator. It's looking like the alternator can't sustain 14v over time. I ran jumper wires from battery terminals to the driver seat, attached them to my DMM and held idle between 1500-2000. I have a manual toggle switch for the fan as well as thermoswitch. At first I played around with the fan low speed and DMM was reading solid 14v. I turned the fan off and simply held idle at 1500 rpm and watched the DMM reading dropping over a period of maybe 5-10min...about the time it took the engine to get to 160 degrees on a 90 degree day. Over that time the DMM dropped to 13.7 and was continuing to drop. Maybe .01 every minute or two. That was without the fan on or any accessories on.
I probably should have let the engine idle longer to see how far the DMM would drop. I forget what the threshold voltage is for an alternator to be effectively charging the battery. IIRC it's around 13.6v? But with the DMM dropping so consistently without the fan even running I figured I'd seen all I need to see.
Opinions?
I probably should have let the engine idle longer to see how far the DMM would drop. I forget what the threshold voltage is for an alternator to be effectively charging the battery. IIRC it's around 13.6v? But with the DMM dropping so consistently without the fan even running I figured I'd seen all I need to see.
Opinions?
A couple of details:
Battery resting voltage, fully charged =12.6V at about 70*f. That's 2.1 v per cell, 6 cells.
Normal operating voltage of a car is 13.6-14.4v
When you start the car electricity is used. Alt needs to replace the current used. Thus the Alt will charge at 14.1 until battery charged back up. Once batt is charged, the voltage reg will pull back to a static 13.6-13.8 volts. At this voltage, the battery will not overcharge. If the alternator charges at that 14.1 once the batt is full charge, it may boil off electrolyte.
Add in that the voltage of a fully charged battery varies with the temp and I think you are ok.
As an aside, my Sweetness Taurus alt will initially show 14.1 volts at start up. As I drive, it declines to about 13.8v. It's never gone much lower, including running my Mighty Mark VIII Lincoln fan on high, full A/C system, stereo with some thump in the trunk, lights on at night, stopped at a stoplight, brake lights on too. I used to wonder if it was ok, but now I accept that as normal.
I think you are ok.
08-26-13, 09:46 PM
#24
I think this is totally normal behavior for a car charging system.
A couple of details:
Battery resting voltage, fully charged =12.6V at about 70*f. That's 2.1 v per cell, 6 cells.
Normal operating voltage of a car is 13.6-14.4v
When you start the car electricity is used. Alt needs to replace the current used. Thus the Alt will charge at 14.1 until battery charged back up. Once batt is charged, the voltage reg will pull back to a static 13.6-13.8 volts. At this voltage, the battery will not overcharge. If the alternator charges at that 14.1 once the batt is full charge, it may boil off electrolyte.
Add in that the voltage of a fully charged battery varies with the temp and I think you are ok.
As an aside, my Sweetness Taurus alt will initially show 14.1 volts at start up. As I drive, it declines to about 13.8v. It's never gone much lower, including running my Mighty Mark VIII Lincoln fan on high, full A/C system, stereo with some thump in the trunk, lights on at night, stopped at a stoplight, brake lights on too. I used to wonder if it was ok, but now I accept that as normal.
I think you are ok.
A couple of details:
Battery resting voltage, fully charged =12.6V at about 70*f. That's 2.1 v per cell, 6 cells.
Normal operating voltage of a car is 13.6-14.4v
When you start the car electricity is used. Alt needs to replace the current used. Thus the Alt will charge at 14.1 until battery charged back up. Once batt is charged, the voltage reg will pull back to a static 13.6-13.8 volts. At this voltage, the battery will not overcharge. If the alternator charges at that 14.1 once the batt is full charge, it may boil off electrolyte.
Add in that the voltage of a fully charged battery varies with the temp and I think you are ok.
As an aside, my Sweetness Taurus alt will initially show 14.1 volts at start up. As I drive, it declines to about 13.8v. It's never gone much lower, including running my Mighty Mark VIII Lincoln fan on high, full A/C system, stereo with some thump in the trunk, lights on at night, stopped at a stoplight, brake lights on too. I used to wonder if it was ok, but now I accept that as normal.
I think you are ok.
I still have the problem with the charging system at first keeping up with the efan and then suddenly not being able to. I haven't driven it since it last did it, but I have no reason to believe it has suddenly cured itself. When time permits I'll do the same test but not abort it before the fan kicks in.
For what it's worth, if the alternator proves to be the problem I'm going to go with a Taurus alt. If someone else can make the alt fit under the TMIC I can also.
08-30-13, 03:38 PM
#25
I bought a 50a analog meter, the kind you mount, not a multimeter type. I want to see how many amps this fan is pulling. I might also buy a 140a one so I can test my alternator.
I tried running the test yesterday with the 50a meter in series with the fan +. And my DMM with jumper leads running from battery terminals to the driver seat. I'm testing it solo with the meter sitting on my radiator panel so I can't see what it spikes to on turn on, but it settles down to surprisingly low. On high I'm seeing below 20a...very different from the youtube videos of people doing the same test with the same fan. Videos I've seen they are seeing 30a or more.
Anyway, I idled the engine at 2k and flipped the manual override switch and haven't seen too much different. I watch the DMM dropping. My batteries in the DMM went dead but before it blinked out I was seeing 13.5ish (I'd have to look at my notes for actual numbers).
Tonight or over the weekend I'm going to run the jumper leads off the alternator rather than the battery, get a better idea of what the alternator is doing. I'm thinking I'll simply go through all the wiring for the fan again. Replace the relays, possibly do like Akagi suggested and switch the relay to the positive rather than the negative
I tried running the test yesterday with the 50a meter in series with the fan +. And my DMM with jumper leads running from battery terminals to the driver seat. I'm testing it solo with the meter sitting on my radiator panel so I can't see what it spikes to on turn on, but it settles down to surprisingly low. On high I'm seeing below 20a...very different from the youtube videos of people doing the same test with the same fan. Videos I've seen they are seeing 30a or more.
Anyway, I idled the engine at 2k and flipped the manual override switch and haven't seen too much different. I watch the DMM dropping. My batteries in the DMM went dead but before it blinked out I was seeing 13.5ish (I'd have to look at my notes for actual numbers).
Tonight or over the weekend I'm going to run the jumper leads off the alternator rather than the battery, get a better idea of what the alternator is doing. I'm thinking I'll simply go through all the wiring for the fan again. Replace the relays, possibly do like Akagi suggested and switch the relay to the positive rather than the negative