Now I have a damn electrical problem...
11-11-02, 06:33 PM
#1
Now I have a damn electrical problem...
Ok, For the past few days Ive been driving around town with no problems whatsoever. Now, all of a sudden today I hopped in my car, went to start it, no dice. The starter turns, just real slow. I had to push start it. I figured, Id just drive it and see what happenes. Well, I drove it for about 15 minutes to the hardware store, got out, went it, bought the stuff, came out, battery is dead...Again. WTF? Ok, now Im wondering. I drove it to the junk yard looking for some treasures, and had my friend sit in it while it was running while I went in, thinking it would charge. I was in there for a good 30 minutes, came out, and drove the 15 minutes home. So thats a good 45 minutes of running to charge it. Got home, shut it off, turned the key to start it again, real slow, no dice. What the hell? The voltage gauge is normal while I drive (~13-14 volts), but it drops to ~8 everytime I try and start it. My only guess is that since I have my electric fan wired to run after the car is shut off, its draining the battery. Duh you say, but why did it take this long to start doing it?
~T.J.
~T.J.
11-11-02, 06:35 PM
#2
Oh yeah, and Im sure I need a new starter...I think maybe its also contributing to the problem by drawing too much voltage...But the problem remains...Everytime I shut the key off, and then turn it on again, the gauge only read 8 volts...Even though its charging "normally".
~T.J.
~T.J.
11-11-02, 06:53 PM
#3
Admitted 'rexaholic'
Mine turned slow as well, would barely start. Voltages read ok! Replaced battery cables, spins like a champ now. That would be my first guess, besides the battery itself.
11-11-02, 06:55 PM
#4
Yeah. Well for now, Im just gonna wire the fan to only come on when the key is on to save myself...I just need to know which terminal of the coil I can hook the igntion wire to. Anyone know? I checked it witha volt meter, but all 4 wire terminals on the coils read 12V when the key is on...Which one am I supposed to hook it to?
~T.J.
~T.J.
11-11-02, 07:32 PM
#5
Open up! Search Warrant!
Join Date: May 2002
Location: Kicking down doors in a neighborhood near you
Posts: 3,838
Likes: 0
Received 2 Likes
on
2 Posts
How old is the battery? If its old as hell it may not be taking a charge, time for a new one. If the alternator is not sending the charge, you need a new alt. I always start the car and unplug the battery while its running. If the engine dies, the alternator is not working right. While you have the cables off the battery, you can use a volt meter to check the volts going to the battery. Should be 14-16 volts going to the battery to charge it. If not, may want to consider replacing the alt unless you know how to rebuild them. It isn't recommended unpluging the battery while the engine is running on newer cars that have computers that do everything except scratch your ***, although I've done it and never burned anything out.
11-11-02, 07:48 PM
#7
Ok...Update. Initial test showed a strog alternator. I had the car idling, and the battery read about 12.8 volts, the alternators output (measured by + lead of voltmeter on output wire, - lead on housing of alt) read 13.8 volts. So I just rewired the fan to the ignition turn on for the coils, and took it for a test drive thinking all was well. I got out on the road, and anything below 2K RPMs, the cars tach goes goofy and the volt meter drops to 10 volts. I jumped out at a gas station, and read the output of the alt...9 volts. The battery had 8 volts, and was slowly dropping. I disconnected the fan to see if that would help (pulled the fuse). Both readings went up about .5 volts, but it was still sad. I barely made it home, the car was dying unless I was holding it at 3K. When I got home, I shut it off, turned the key back on, gauge reads ~6 volts...If its not one thing its another...Damn it 
.
~T.J.
.~T.J.
Trending Topics
11-11-02, 08:36 PM
#8
Retro Rocket
Damn, TJ, ur having the worst luck I think you either have a shorted cell in your battery, or the alt is on it's last legs. Or both. When the alternator starts to go out, it will usually be intermittant for awhile. Sometimes, a little "technical tap " with a hammer while it's running will reseat the brushes. When mine went, Mazda wanted like 300 bucks for a new alternater 
I took mine to one of those alternator/starter exchange places (every city has one) and they rebuilt it for about $75. Still wasn't cheap, but worked like new.
I think you either have a shorted cell in your battery, or the alt is on it's last legs. Or both. When the alternator starts to go out, it will usually be intermittant for awhile. Sometimes, a little "technical tap " with a hammer while it's running will reseat the brushes. When mine went, Mazda wanted like 300 bucks for a new alternater I took mine to one of those alternator/starter exchange places (every city has one) and they rebuilt it for about $75. Still wasn't cheap, but worked like new.
11-11-02, 08:49 PM
#10
Try cleaning the terminals and check the ground and positive connections to the starter, as well as the chassis ground connection. Even if the charging system is working properly, oxidation can build up on the terminals, creating a high resistance and causing problems very much like the symptoms you describe. You should occasionally make a slurry out of baking soda and water and clean the terminals as well as the whole battery mounting area. That will neutralize any acid present as well as providing some cheap entertainment when it bubbles and sizzles. Once you have eliminated the mechanical connections as a source of the problem, then you should start looking at the charging system itself, the alternator, regulator, and the battery. Electrical problems are best diagnosed one step at a time, eliminating the most obvious possibilities first. Hooking a motor up to the +terminal of the coil may cause some modulation due to the electric motor's commutator brushes making and breaking contact. That could cause the tach to behave strangely. I'd try to hook the fan up to the same wire that feeds the fuel pump, and hope that the fuse doesn't blow. Good luck!
-Mike
-Mike
11-11-02, 09:17 PM
#11
Ok, well the grounds are clean. I took them all off, and wire brushed the chasis and the terminals on which they attach, and re-attached them. No change. The battery terminals were cleaned with a post terminal cleaner, no change.
~T.J.
~T.J.
11-12-02, 12:23 AM
#12
Open up! Search Warrant!
Join Date: May 2002
Location: Kicking down doors in a neighborhood near you
Posts: 3,838
Likes: 0
Received 2 Likes
on
2 Posts
If I were in your shoes, what I would do at this point is start searching for a battery, or alt. Buy which ever is cheaper to replace, and replace them one at a time till the problem goes away. Ebay is a good venue for cheap RX-7 alternators, but yours may not last long enough for you to wait for an auction to end and the part to be shipped to you. Here are a couple links to alternators on ebay.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1871797488
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1872193669
Those two end within 24hrs.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1871797488
http://cgi.ebay.com/ebaymotors/ws/eB...tem=1872193669
Those two end within 24hrs.
11-12-02, 12:50 AM
#13
T.J.
Did you say that you wired up the fan to the ignition coil/s? That's not good
Leave them be to supply energy for spark! The tachometer runs off the trailing coil, hence the bouncing needle..also a good way to see if the ignitors are going bad.
Did you say that you wired up the fan to the ignition coil/s? That's not good
Leave them be to supply energy for spark! The tachometer runs off the trailing coil, hence the bouncing needle..also a good way to see if the ignitors are going bad.
11-12-02, 12:52 AM
#14
Full Member
Join Date: Apr 2002
Location: birmingham alabama
Posts: 116
Likes: 0
Received 0 Likes
on
0 Posts
hmm
ok ...dammit... maybe this is part of whats wrong with my car.... my battery always shows up at 10 volts for some reason(!?) and my car wont stay idling unless i hold it at 3k...and omfg..i have every single thing torn down on my car and it could be this stupid electrical problem...good god.. *sigh* time to start putting s*it back together....
question though....if you hold the choke out on your car will it idle itself (mine would idle itself with choke pulled out at 1700RPM, but if i budged the choke in it would DIE flat out).....
question though....if you hold the choke out on your car will it idle itself (mine would idle itself with choke pulled out at 1700RPM, but if i budged the choke in it would DIE flat out).....
11-12-02, 08:34 AM
#15
Airflow is my life
Originally posted by RotorMotorDriver
Yeah. Well for now, Im just gonna wire the fan to only come on when the key is on to save myself...I just need to know which terminal of the coil I can hook the igntion wire to. Anyone know? I checked it witha volt meter, but all 4 wire terminals on the coils read 12V when the key is on...Which one am I supposed to hook it to?
~T.J.
Yeah. Well for now, Im just gonna wire the fan to only come on when the key is on to save myself...I just need to know which terminal of the coil I can hook the igntion wire to. Anyone know? I checked it witha volt meter, but all 4 wire terminals on the coils read 12V when the key is on...Which one am I supposed to hook it to?
~T.J.
11-12-02, 08:35 AM
#16
Airflow is my life
Originally posted by RotorMotorDriver
Ok, well the grounds are clean. I took them all off, and wire brushed the chasis and the terminals on which they attach, and re-attached them. No change. The battery terminals were cleaned with a post terminal cleaner, no change.
~T.J.
Ok, well the grounds are clean. I took them all off, and wire brushed the chasis and the terminals on which they attach, and re-attached them. No change. The battery terminals were cleaned with a post terminal cleaner, no change.
~T.J.
11-12-02, 10:29 AM
#17
Originally posted by Rx7carl
Did you remove and clean the one at the engine? behind the oil filter pedestal? Thats the main engine ground. You need it for the alt and plugs to have a good ground.
Did you remove and clean the one at the engine? behind the oil filter pedestal? Thats the main engine ground. You need it for the alt and plugs to have a good ground.
Where else can I hook the fan up to only have power when the key is on? Or should I just forget that, and wire it up the way it used to be (on until the radiator is cooled) cause in theroy I shouldnt have problems?
~T.J.
11-12-02, 10:44 AM
#18
Airflow is my life
Well you want the quick/easy way? Sorry I dont work like that 
. I have mine with a dedicated wire off the battery (inline fuse of course) to a switch in the cockpit. I am lucky enough to have a heavy duty aircraft switch that can easliy handle the amps. You would have to install a relay or your switch wont last. You could also tap off the fusebox on an unused ign on source to power the fan, then it would be fused, and run ign on only. Those t/stats for the fans suck anyway, been thru 2, then went with the switch.
. I have mine with a dedicated wire off the battery (inline fuse of course) to a switch in the cockpit. I am lucky enough to have a heavy duty aircraft switch that can easliy handle the amps. You would have to install a relay or your switch wont last. You could also tap off the fusebox on an unused ign on source to power the fan, then it would be fused, and run ign on only. Those t/stats for the fans suck anyway, been thru 2, then went with the switch.
11-12-02, 10:59 AM
#19
Those t/stats for the fans suck anyway, been thru 2
.As far as how to do it, I just thought it was cool it kept running until the radiator cooled down. Then, when that was causing a problem (so I thought), I went to hook it up only on when the key is on, but you people say to not do it there. So now what? In theroy, if my charging system is working right, I should be able to have it run with the car off, right? So if I figure out my problem, I can just hook it back up that way?
~T.J.
11-12-02, 01:52 PM
#20
Airflow is my life
I guess. I would prefer ign on only. The stock fan doesnt turn when the motor is shut off so why would an electric one need to? Sorry, dont mean to jinx u, shhhhhh.............
11-12-02, 03:38 PM
#21
Hunting Skylines
Join Date: Apr 2001
Location: Brisbane, Queensland, Australia.
Posts: 3,431
Likes: 0
Received 2 Likes
on
2 Posts
TJ, are you running a thermo switch? If so, then you can run the trigger wire to one of the ignition coils, no worries at all. But, the main feed to the fan should always come straight off the battery. On mine, the thermo switch triggers a set of relays which then turn on the fans.
Thermo switches are the only way to go on a street car.
The quality Davies-Craig one I'm using has worked perfectly for years now. Just set it to come on at the right temp. and forget about it. The ones that place the sensor in the fins of the radiator are definately junk though.
Thermo switches are the only way to go on a street car.
The quality Davies-Craig one I'm using has worked perfectly for years now. Just set it to come on at the right temp. and forget about it. The ones that place the sensor in the fins of the radiator are definately junk though.
11-12-02, 04:00 PM
#22
Right near Malloy
iTrader: (28)
Join Date: Dec 1999
Location: Behind a workbench, repairing FC Electronics.
Posts: 7,841
Received 510 Likes
on
345 Posts
Try jumpstarting the car and seeing if the Starter cranks slowly... It sounds like a classic case of shot battery.
I don't think you ever did say how old it is... Set it on the charger overnight.
See if you can get a hold of a clamp on Ammeter. It clamps around a wire and reads the current passing through it. Clamp it around the big wire off the back of the Alternator... Then turn on EVERYTHING... Lights, interior fan, etc... Alternator should put out more than a few amps... Peak should be 55 A on a stocker. With the battery, it should be something like 20-30...
Most major auto parts stores test alternators and starters for free.
If jump starting it works, then it's the alternator that's bad.
If the charger works, try charging it overnight, then letting it sit by itself for a day, disconnected from the car. Reconnect it and try starting. If that works, then the battery will hold a charge and is good... After that, leave it connected to the car, not running for a few hours, or maybe a day. Try starting. If the battery is dead, you have a power drain (Something left on or stuck on). Alternatively, you can get a test light ($20 or less, looks like a screwdriver with a clear handle and a wire on the end.) and disconnect the negative terminal. Clip the test light to the battery cable terminal, and stick the point to the battery terminal itself. The light should not light. If it does, touch the cable to the battery, and remove it again. It should be out. (Sometimes the radio or ECU memory takes a little bit of power to charge up. After it's charged, it shouldnt take any power.)
If it ends up being a power drain somewhere, I'l walk you through that, this post is long enough already.
I don't think you ever did say how old it is... Set it on the charger overnight.
See if you can get a hold of a clamp on Ammeter. It clamps around a wire and reads the current passing through it. Clamp it around the big wire off the back of the Alternator... Then turn on EVERYTHING... Lights, interior fan, etc... Alternator should put out more than a few amps... Peak should be 55 A on a stocker. With the battery, it should be something like 20-30...
Most major auto parts stores test alternators and starters for free.
If jump starting it works, then it's the alternator that's bad.
If the charger works, try charging it overnight, then letting it sit by itself for a day, disconnected from the car. Reconnect it and try starting. If that works, then the battery will hold a charge and is good... After that, leave it connected to the car, not running for a few hours, or maybe a day. Try starting. If the battery is dead, you have a power drain (Something left on or stuck on). Alternatively, you can get a test light ($20 or less, looks like a screwdriver with a clear handle and a wire on the end.) and disconnect the negative terminal. Clip the test light to the battery cable terminal, and stick the point to the battery terminal itself. The light should not light. If it does, touch the cable to the battery, and remove it again. It should be out. (Sometimes the radio or ECU memory takes a little bit of power to charge up. After it's charged, it shouldnt take any power.)
If it ends up being a power drain somewhere, I'l walk you through that, this post is long enough already.
11-12-02, 07:06 PM
#23
TJ, are you running a thermo switch? If so, then you can run the trigger wire to one of the ignition coils, no worries at all.
I don't think you ever did say how old it is...
Ok. I got a new alternator and starter. I slapped the alt in there, and fired it up (had to push start it). Anyway, everything seemed ok as I took it for a spin around the block. The alt was outputting 13.5 volts steady, and the battery had a little over 13 volts in it. I figured "well cool". I drove the few blocks to the mall, parked, got out, went in to Sears to check out their batteries (cause I know I need a new on), came out, turned the key, and it fired right up. Started driving home, rolled up the window, and all of a sudden the volt gauge started going wacko. Anyway, the car started doing the 15 volt charge when driving 12 volts when sitting around at a stoplight. Then it started getting worse. Stoplight, 9 volts, revving 16 volts, then I noticed the lights brigtening and dimming in relation to the RPMs...Typical for voltage regulator. The car BARELY got me home, dying as I coasted into my parking space. I turned the headlights off, but they didnt go down
. I got out, and checked the fusable links. The main one was fried. Great. I think the alt fried itself trying to charge my dead battery . ****, I knew I should have bought a damn new battery . You think its too late for it now?~T.J.
11-12-02, 08:15 PM
#25
Airflow is my life
quote:
--------------------------------------------------------------------------------
TJ, are you running a thermo switch? If so, then you can run the trigger wire to one of the ignition coils, no worries at all.
--------------------------------------------------------------------------------
Thats what I did and everyone freaked!!
you said you were powering the fan directly from the coil. THAT IS BAD. Re read what revhead said. Are you..... or are you not using a relay? And the crappy t/stats is what revhead is talking about being bad, just like my bad experiences.....they are ****. A good thermoswitch like he said would be good way to go. But I'm a cheap bastard and prefer ign powered only.hehe
--------------------------------------------------------------------------------
TJ, are you running a thermo switch? If so, then you can run the trigger wire to one of the ignition coils, no worries at all.
--------------------------------------------------------------------------------
Thats what I did and everyone freaked!!
you said you were powering the fan directly from the coil. THAT IS BAD. Re read what revhead said. Are you..... or are you not using a relay? And the crappy t/stats is what revhead is talking about being bad, just like my bad experiences.....they are ****. A good thermoswitch like he said would be good way to go. But I'm a cheap bastard and prefer ign powered only.hehe
Last edited by Rx7carl; 11-12-02 at 08:17 PM.