Electrical - current drain and damn gas gauge.
12-25-03, 01:25 AM
#1
Refined Valley Dude
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Electrical - current drain and damn gas gauge.
First up, my mystery current drain.
I have never been able to let my 7 sit for more than 2 days without risking being unable to start her due to a flattened battery. This sucks. So tonight I disconnected my neg battery cable (after keying the ignition completely off,) put my multimeter in line with it and started yanking fuses.
I have a 0.18 amp drain between the fuses and the battery. I pulled EVERYTHING but the MAIN fuse in the engine bay. This includes disconnecting my e-fan and my stereo and CD player, and the big fat HEATER and DEFOG blocks from the fuse box.
I'm hoping for suggestions on likely places to start checking for shorts, as well as a step-by-step on checking wires. I should mention here that I have had to put a 10A fuse into the 'ROOM' slot b/c 7.5A ones kept blowing - I'd call that a hint.
Next up is the gas gauge. Yes, I've searched.
Pretty much since Day 1 with this body, the gas gauge has been useless. But the Low Fuel sensor/light has worked just fine. I salvaged the A-OK fuel pump from my first FC and finally slapped it in tonight.
The goddamn gauge is still flat.
Otherwise, the pump and Low Fuel sensor/light are working perfectly.
So now I'm thinking its either the wire or the gauge. It was too late to start digging around behind the cluster. My s4 FSM has procedures for checking the pump, but I didn't see anything for checking the gauge itself. I'll give it a once-over for any obvious damage.
Any pointers on checking things at the instrument cluster?
I have never been able to let my 7 sit for more than 2 days without risking being unable to start her due to a flattened battery. This sucks. So tonight I disconnected my neg battery cable (after keying the ignition completely off,) put my multimeter in line with it and started yanking fuses.
I have a 0.18 amp drain between the fuses and the battery. I pulled EVERYTHING but the MAIN fuse in the engine bay. This includes disconnecting my e-fan and my stereo and CD player, and the big fat HEATER and DEFOG blocks from the fuse box.
I'm hoping for suggestions on likely places to start checking for shorts, as well as a step-by-step on checking wires. I should mention here that I have had to put a 10A fuse into the 'ROOM' slot b/c 7.5A ones kept blowing - I'd call that a hint.
Next up is the gas gauge. Yes, I've searched.
Pretty much since Day 1 with this body, the gas gauge has been useless. But the Low Fuel sensor/light has worked just fine. I salvaged the A-OK fuel pump from my first FC and finally slapped it in tonight.
The goddamn gauge is still flat.
Otherwise, the pump and Low Fuel sensor/light are working perfectly.So now I'm thinking its either the wire or the gauge. It was too late to start digging around behind the cluster. My s4 FSM has procedures for checking the pump, but I didn't see anything for checking the gauge itself. I'll give it a once-over for any obvious damage.
Any pointers on checking things at the instrument cluster?
Last edited by Amur_; 12-25-03 at 01:28 AM.
12-25-03, 11:00 AM
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HAILERS
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Disconnect the alternator wire at the alternator and see what happens. The large feed wire.
Look harder in the fsm for checking out the fuel gauge. It's there.
Or how about this.....pull each fuse one at a time and then put your meter on amps and put the leads across the prongs the fuse attaches to and read the meter. Look at the BTN fuse especially. Do it with the key out.
I think the BTN is the only one you should expect to see anything. Except the Main Fuse which you'll have to unbolt at least one wire/bolt from to read as above.
Look harder in the fsm for checking out the fuel gauge. It's there.
Or how about this.....pull each fuse one at a time and then put your meter on amps and put the leads across the prongs the fuse attaches to and read the meter. Look at the BTN fuse especially. Do it with the key out.
I think the BTN is the only one you should expect to see anything. Except the Main Fuse which you'll have to unbolt at least one wire/bolt from to read as above.
12-25-03, 03:16 PM
#4
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Originally posted by Scott 89t2
so the amps never change even when all the fuses are out?
so the amps never change even when all the fuses are out?
Correctamundo.
Originally posted by HAILERS
Disconnect the alternator wire at the alternator and see what happens. The large feed wire.
Look harder in the fsm for checking out the fuel gauge. It's there.
Or how about this.....pull each fuse one at a time and then put your meter on amps and put the leads across the prongs the fuse attaches to and read the meter. Look at the BTN fuse especially. Do it with the key out.
I think the BTN is the only one you should expect to see anything. Except the Main Fuse which you'll have to unbolt at least one wire/bolt from to read as above.
Disconnect the alternator wire at the alternator and see what happens. The large feed wire.
Look harder in the fsm for checking out the fuel gauge. It's there.
Or how about this.....pull each fuse one at a time and then put your meter on amps and put the leads across the prongs the fuse attaches to and read the meter. Look at the BTN fuse especially. Do it with the key out.
I think the BTN is the only one you should expect to see anything. Except the Main Fuse which you'll have to unbolt at least one wire/bolt from to read as above.
12-26-03, 12:30 AM
#5
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Alright, here are the results.
Left all fuses in, disconnecting only direct-wired systems (and I closed the doors.)
The meter read 0.04 amps. Don't ask me to explain it. I can't.
I'll assume that whatever bouncing around happened while I was driving in the time between these checks moved the short around or something... I don't know.
Pissed off at this, I then jumped ahead to what was going to be project #2 for the evening. I pulled all of the 4-gauge wire I had installed to mirror the charging system and re-soldered the connectors. Then I went back to looking for the current drain...
Here's what I got...
All fuses removed except ROOM and MAIN -- 0.04 amps. When I removed ROOM and put the probes to the fuse slot, it showed the 0.01 amp draw. No other fuse slot showed a draw throughout this check.
All fuses removed except MAIN -- 0.03 amps.
Removed MAIN - it twitched between 0.03 and 0.02, never quite settling.
Removed lead from alternator -- 0.00 amps.
Now here's the weird part. There are two wires coming from the alt's positive post. One is the stock wire, and the other is a 4-gauge wire that I added that goes down to the starter motor. If both wires were on the post, I showed a drain of 0.03 amps. If only one wire touched the post (didn't matter which one) then the drain vanished.
So I'm now losing 0.01 amps to the short in the ROOM circuit, a smidge to the MAIN circuit (which I believe is normal from what I've read,) and something is happening with the alt/starter that's inhaling 0.03 amps...
My extra wires to mirror the charging system are:
- battery positive post to starter positive post.
- MAIN fuse to starter positive post.
- alternator to starter positive post (yes, it's crowded down there. )
- I have been considering adding a wire from the alt to the battery positive post, but haven't yet done it...
All are 4-gauge wires.
So what's the deal with the alt, then?
Left all fuses in, disconnecting only direct-wired systems (and I closed the doors.)
The meter read 0.04 amps. Don't ask me to explain it. I can't.
I'll assume that whatever bouncing around happened while I was driving in the time between these checks moved the short around or something... I don't know.Pissed off at this, I then jumped ahead to what was going to be project #2 for the evening. I pulled all of the 4-gauge wire I had installed to mirror the charging system and re-soldered the connectors. Then I went back to looking for the current drain...
Here's what I got...
All fuses removed except ROOM and MAIN -- 0.04 amps. When I removed ROOM and put the probes to the fuse slot, it showed the 0.01 amp draw. No other fuse slot showed a draw throughout this check.
All fuses removed except MAIN -- 0.03 amps.
Removed MAIN - it twitched between 0.03 and 0.02, never quite settling.
Removed lead from alternator -- 0.00 amps.
Now here's the weird part. There are two wires coming from the alt's positive post. One is the stock wire, and the other is a 4-gauge wire that I added that goes down to the starter motor. If both wires were on the post, I showed a drain of 0.03 amps. If only one wire touched the post (didn't matter which one) then the drain vanished.
So I'm now losing 0.01 amps to the short in the ROOM circuit, a smidge to the MAIN circuit (which I believe is normal from what I've read,) and something is happening with the alt/starter that's inhaling 0.03 amps...
My extra wires to mirror the charging system are:
- battery positive post to starter positive post.
- MAIN fuse to starter positive post.
- alternator to starter positive post (yes, it's crowded down there.
)- I have been considering adding a wire from the alt to the battery positive post, but haven't yet done it...
All are 4-gauge wires.
So what's the deal with the alt, then?
12-26-03, 12:58 AM
#7
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Originally posted by J-Rat
I fixed my fuel gauge by removing the dash cluster, and cleaning all the contacts.
I fixed my fuel gauge by removing the dash cluster, and cleaning all the contacts.
****! Forgot about that!
I did the test in section 15. Connected the probes.
Key off - 1.04k
Key on - error (meaning I got a '1' all by itself on the left side of the display)
Key off again - .595k
The needle in the gauge never budged, and hasn't budged since putting the replacement pump in.
Time to check out the cluster this weekend.
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12-26-03, 01:14 AM
#9
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Originally posted by J-Rat
Can I ask a question here?
Why did you run a positive from your alt to the starter?
Can I ask a question here?
Why did you run a positive from your alt to the starter?
This is from a thread talking about the FC alt's crappy output...
Originally posted by hypntyz7
The best way to attack this is to save up a couple hundred and a weekend to revamp your entire charging system. I had these same problems on my 87 t2, and with an e-fan and stereo(and foglights) it just wanst going to work.
I got a nice s5 alternator adn installed it. It is nice if you have the clip to go with it, but you can do as described above and use 2 female speaker terminals to connect the wires to the alternator. IF you look in the FSM and on the back of the alternators, you can see S and L, just match those leads back up. You can use an na alt. on a t2 adn vice versa, just loosen and rotate the battery post on teh back of the alt.
Before, even without the e-fan, I would see a max of 13vdc at idle, usually closer to 12.5. I bought a new battery, a 925CA battery from walmart, the biggest baddest one they sell, was only 59 bucks with a 7 year prorated warranty. I bought 2 new posts, and 25 feet of 4 gauge stereo power wire, alogn with appropriate connectors. I did this because I was relocating my battery to the hatch at teh same time, so you wont need more than a few feet for a stock application.
I ran new wire from:
-my battery ground to the chassis using a bolt, a large washer, and ground down to the sheetmetal.
-my batter + to the starter terminal, clean the starter connection when doing so
-my alternator + post to the starter + terminal
-the fusebox main power supply (underhood 80A fuse) to the starter + terminal
-the starter frame(engine) to the chassis, cleaning and grinding both surfaces down to bare metal.
Then I ditched all teh stock wiring left over. You have now rewired your entire main charging circuit. Simple isnt it?
IF youre keeping stock battery location, do the above with new battery cables and terminals. Keep the connections clean. Replace every wire and connector(total cost less than $50) and you'll get a LOT of power in return.
So, what do I see now?
daytime cruise 15vdc on the highway, 14.5 at idle, 14+ at night with all the lights on. BIG difference. Helps a lot with starting/flooding issues on the engine too, when the starter can actually kick the engine over pretty hard, it starts on teh first rotation.
I give it a 10, and it should be one of the first things done to an old car that youre going to keep/modify.
The best way to attack this is to save up a couple hundred and a weekend to revamp your entire charging system. I had these same problems on my 87 t2, and with an e-fan and stereo(and foglights) it just wanst going to work.
I got a nice s5 alternator adn installed it. It is nice if you have the clip to go with it, but you can do as described above and use 2 female speaker terminals to connect the wires to the alternator. IF you look in the FSM and on the back of the alternators, you can see S and L, just match those leads back up. You can use an na alt. on a t2 adn vice versa, just loosen and rotate the battery post on teh back of the alt.
Before, even without the e-fan, I would see a max of 13vdc at idle, usually closer to 12.5. I bought a new battery, a 925CA battery from walmart, the biggest baddest one they sell, was only 59 bucks with a 7 year prorated warranty. I bought 2 new posts, and 25 feet of 4 gauge stereo power wire, alogn with appropriate connectors. I did this because I was relocating my battery to the hatch at teh same time, so you wont need more than a few feet for a stock application.
I ran new wire from:
-my battery ground to the chassis using a bolt, a large washer, and ground down to the sheetmetal.
-my batter + to the starter terminal, clean the starter connection when doing so
-my alternator + post to the starter + terminal
-the fusebox main power supply (underhood 80A fuse) to the starter + terminal
-the starter frame(engine) to the chassis, cleaning and grinding both surfaces down to bare metal.
Then I ditched all teh stock wiring left over. You have now rewired your entire main charging circuit. Simple isnt it?
IF youre keeping stock battery location, do the above with new battery cables and terminals. Keep the connections clean. Replace every wire and connector(total cost less than $50) and you'll get a LOT of power in return.
So, what do I see now?
daytime cruise 15vdc on the highway, 14.5 at idle, 14+ at night with all the lights on. BIG difference. Helps a lot with starting/flooding issues on the engine too, when the starter can actually kick the engine over pretty hard, it starts on teh first rotation.
I give it a 10, and it should be one of the first things done to an old car that youre going to keep/modify.
Good enough for Kevin, good enough for me.
12-26-03, 01:47 AM
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Originally posted by Scott 89t2
so what happened to the 0.18 ?? it's gone?
so what happened to the 0.18 ?? it's gone?
I'll check again the next few times I'm working on the car; see if it comes back.
the room drain is normal. that's your clook etc.
Now I just need to know what's up with those alt lines.
12-26-03, 10:30 AM
#14
Former Moderator. RIP Icemark.
Anything over .07-.08 will draw the battery down in a couple of days or less.
The extra .14 A suggestes a bulb is on, as that is typically what a 5 watt bulb pulls.
Check your rear hatch light and switches. Often if they get wet from the rear hatch seal leaking (or trunk seal on convertibles) the switch will leak voltage and start intermittently turning on the rear area light.
The extra .14 draw could also be a couple of relays if something aftermarket was incorrectly wired in like a stereo.
The extra .14 A suggestes a bulb is on, as that is typically what a 5 watt bulb pulls.
Check your rear hatch light and switches. Often if they get wet from the rear hatch seal leaking (or trunk seal on convertibles) the switch will leak voltage and start intermittently turning on the rear area light.
The extra .14 draw could also be a couple of relays if something aftermarket was incorrectly wired in like a stereo.
12-26-03, 07:16 PM
#15
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Originally posted by Icemark
Anything over .07-.08 will draw the battery down in a couple of days or less.
Anything over .07-.08 will draw the battery down in a couple of days or less.
Can't argue with that.
The extra .14 A suggestes a bulb is on, as that is typically what a 5 watt bulb pulls.
Check your rear hatch light and switches. Often if they get wet from the rear hatch seal leaking (or trunk seal on convertibles) the switch will leak voltage and start intermittently turning on the rear area light.
Check your rear hatch light and switches. Often if they get wet from the rear hatch seal leaking (or trunk seal on convertibles) the switch will leak voltage and start intermittently turning on the rear area light.
So noted about the light bulb, but...
The rear hatch light is always switched off, and was off during the check. I have never seen evidence of a leak anywhere around the rear hatch nor anywhere in the rear of the car (unlike my last FC, whose hatch leaked like Edward Scissorhands' waterbed.)
I'll make a point of double-checking that light just the same the next time I check for a drain.
The extra .14 draw could also be a couple of relays if something aftermarket was incorrectly wired in like a stereo.
I wired in the stereo equip myself. The stereo and CD player each have a single power wire, no relay, and both were disconnected during the check. The amp is switched at the center armrest, and was both switched off and had its fuse pulled during the check.
The only device I have installed myself with a relay on it is for the sleepy lights mod. The power wire for that relay was disconnected during the check and the switch was off...
But I'll keep looking.
Any comment on that 0.03A and those alt wires?
01-11-04, 06:35 PM
#16
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Well, I think the drain is gone for good. Hopefully permanently and not like Freddy.
It's been over 4 full days since I last ran my 7. I expect that most of us know what the temps have been like - overnight lows dipping down to near 0F.
I went down half an hour ago to see if she would start. When I opened the driver's side door the alarm lights were blinking nice and bright. A good sign.
She fired right up.
I don't know what made the difference, but I figured I should share the good news anyway.
It's been over 4 full days since I last ran my 7. I expect that most of us know what the temps have been like - overnight lows dipping down to near 0F.
I went down half an hour ago to see if she would start. When I opened the driver's side door the alarm lights were blinking nice and bright. A good sign.
She fired right up.
I don't know what made the difference, but I figured I should share the good news anyway.
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