Electrical Problem - Any Ideas?
Thread Starter
1st Gear
Joined: Sep 2010
Posts: 1
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Electrical Problem - Any Ideas?
I have a 1980 with an electrical grounding issue of some kind... here's the story.
The car hasn't been driven in a few years and I just bought it. Started up and ran fine, but the battery warning light was on. Had the battery checked and charged and it was fine but the light was still on. Had the alternator checked and it was bad. Replaced the alternator and now the electrical issue has shown up. When I start the car the battery warning light is on and the voltage gauge reads normal. When I close the drivers’ door the battery warning light goes out but the voltage gauge spikes and the engine begins to run rough. Within minutes the battery begins to boil. Closing the drivers’ door triggers the dome light to go out (the light is not currently working) and possible other things... I assume one of these things is causing my problem but I don’t have the expertise to figure this out. The radio seems to have no power, the speedometer is the only gauge that has light, the air/heater/fan is not working, and the turn signal light on the dash works sometimes but not always.
Any thought/ideas/suggestions would be great!!
The car hasn't been driven in a few years and I just bought it. Started up and ran fine, but the battery warning light was on. Had the battery checked and charged and it was fine but the light was still on. Had the alternator checked and it was bad. Replaced the alternator and now the electrical issue has shown up. When I start the car the battery warning light is on and the voltage gauge reads normal. When I close the drivers’ door the battery warning light goes out but the voltage gauge spikes and the engine begins to run rough. Within minutes the battery begins to boil. Closing the drivers’ door triggers the dome light to go out (the light is not currently working) and possible other things... I assume one of these things is causing my problem but I don’t have the expertise to figure this out. The radio seems to have no power, the speedometer is the only gauge that has light, the air/heater/fan is not working, and the turn signal light on the dash works sometimes but not always.
Any thought/ideas/suggestions would be great!!
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Wow, thats an odd one.
Some History? Was the electrical system all working last time it was driven? Were there any electrical mods done? If so, what?
Some things to check;
Wireing on the alternator, Big red wire on the back, small brown wire and small ed wire on the connector on the side of the alt, black ground wire on the bracket for the alternator? Pics?
There is a ground wire post on the AC box that the main engine bay harness is connected to, black wire. The wiper motor and fan are tied to the same post and there should be a braided strap toed to a valve cover bolt or an intake bolt on the passenger side on there too.
On the starter there is a black wire, small with a big ring terminal that should be on the bell housing, sometimes it gets connected to the battery terminal on the starter if the started gets changed, common mistake.
On the pass side under the motor mount there should be a Big black ground wire to the starter bracket
Run through all that and see what happens, better get that new alt looked at too.
Some History? Was the electrical system all working last time it was driven? Were there any electrical mods done? If so, what?
Some things to check;
Wireing on the alternator, Big red wire on the back, small brown wire and small ed wire on the connector on the side of the alt, black ground wire on the bracket for the alternator? Pics?
There is a ground wire post on the AC box that the main engine bay harness is connected to, black wire. The wiper motor and fan are tied to the same post and there should be a braided strap toed to a valve cover bolt or an intake bolt on the passenger side on there too.
On the starter there is a black wire, small with a big ring terminal that should be on the bell housing, sometimes it gets connected to the battery terminal on the starter if the started gets changed, common mistake.
On the pass side under the motor mount there should be a Big black ground wire to the starter bracket
Run through all that and see what happens, better get that new alt looked at too.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The alternator can get rebuilt with the 'sensor' wires in reversed position to the original alternator. Your symptoms would indicate that the alt is on "full charge" the whole time...so it isn't 'seeing' the sensor wire input. The only way to know how it's wired is to take it apart (which will void the warranty). I'd take it back for another one.
Pull the feedback connector out of the alternator and see what happens then. If all the other electrical problems go away (except for the alt light), that may be your problem.
Pull the feedback connector out of the alternator and see what happens then. If all the other electrical problems go away (except for the alt light), that may be your problem.
