I have a 89 GTA and i'm not sure where my problem is coming from. For a little while now, i've noticed at times that the voltage was dropping while sitting still at idle and especially worse when the lights are on. The lights will dim down at idle. If it's raining and hot, with the lights, wipers and the fans going, the voltage will drop as low as 9v on the gauge. I know, don't trust the gauge, but the lights are dim, the wipers are moving very slowly and when i turn the blinker on, it barely blinks. When i start moving and the rpm's come up, it will get better, but not back to where it should be.

I have the 2nd red top Optima battery and the 2nd alternator in the car. Replacing these has not helped the problem. The alternator is a brand new alternator from Carquest, not a reman, so it's not a cheap alternator. I know they can be bad just like any other part though. But, today i was charging the battery back up since i haven't driven the car in about 2 weeks, and noticed the lead from the alternator to the battery had gotten hot and started a melt down. I have a 10ga lead from the alternator to the battery lead with a butt splice. The butt splice is where the melt down was occuring. I replaced it and when i started the engine and let it idle, the wire is getting real hot. Where could the problem be? Tomorrow i'm going to run a direct lead to the battery instead of using that butt splice in the cable end, but i feel it's something else causing it to get hot.

Any help would be greatly appreciated. I'm stumped right now.

Oh yeah, i also have new pos and neg battery cables and cleaned the ground before putting the new neg cable on.

 

Any ideas from anyone on what to check for?

I've checked a few things, but no fix as of yet.

Alt bench tested fine. Battery is fine, red top optima.

 

I'm having similar problems with my 87 Trans Am. It died today while in a drive through. But what I believe my problem is, is that my v-belt isn't tight enough and its slipping and thus, not charging the battery, so I'm going to retighten the belt tomorrow...good luck

 

I've got the serpentine belt and it's new, about 2000 miles on it.

 

yeah, I have new belts too and I even have a new crank pulley. The pulley is powercoated and the ribbed belt is only hand tightened. So I'm going to tighten it with a some sort of vice. Its been raining like crazy the past couple of days and I'm sure everything has gotten wet down there. When I start the car in the mornings, the belts squeal...

 

The only times I had this problem were when my alternator was keeling over dead and back when I installed underdrive pulleys. Those were so bad I had to put the factory ones back on due to the power drop every time I was at a light. Those may not be your answer but at least it can give you an idea what types of issues can cause your problem.

 

I've had the alternator tested, of course it's only a bench test that runs for 30 seconds, but it passed. I've thought about getting the March pulley system for "Power and Amp" kit. But i had to do a cover up instead of fixing the problem.

 

well, today I figured out that my battery died so I just bought a new one. The gentlemen at the different autoparts stores said the battery wouldn't hold a charge...

 

I wish it were that easy for me. I've replaced the alternator and battery. Luckily i got the red top optima replaced free of charge once already, but this one is good. The alternator i had to pay for and bought a new one, not a rebuilt or reman one. I finally took the old alternator i thought was bad to O'reilly and had them check it, they said it was good. So, my old alternator checks fine. I'm at a loss.

 

Is it possible your car is idling too low? If everything is fine while the car is moving, but it dies down while stopped...

Bad cables maybe? Bad connections somewhere? Maybe try replacing old cables and cleaning up all the connection points. I'm not entirely sure of the route of power, but maybe the starter is a problem? My old 79 TA had the fusible link down there burning out till I replaced the old starter. Also check your minimum idle speed. Make sure it's not way too low. If the pulleys are moving too slowly it could prolly cause a situation like I had with the underdrive pulleys.

 

I have new cables and cleaned the point of contact to the block for the neg cable. It idles at about 500rpm in gear. Not sure what the idle should be. But it idles good. So i never thought it was an issue. Who knows. I'm thinking of trying the pulley kit so the alt will spin a little faster.

 

If the wires are still getting warm or hot then maybe thicker cable. The thicker it is the more that can travel through it. just an idea from some past 'experiences' i've had...

 

Yes, get rid of that butt splice, in fact replace the whole wire.. A long thin wire with a (overheating) butt splice screwed up my own charging and gave me a flat battery.. A 10ga wire seems a tad small, it can only handle 55A if single and 33A if in a bundle. A 8ga will handle 73A single and 46A in bundle. Depending on the generator you might want to use a 6ga (101A, single) or even a 4ga (135A, single). With a lenght of 9ft and a current of the max single amps it will introduce a drop of approx 0.5Volts. I would personally prefer to have only half of that drop.

 

any fix to thhis yet? Im having the same problem with mine but I dont have a butt splice, I just have a 10GA wire form the post on the alt straight to the battery, that whole wire gets hot, Im gonna replace both of my battery cables plus use a 4GA wire from the alt to the battery, that seems a little big though, if a wire is getting hot doesnt that mean that there may be a short to ground? Will this bigger wire fix the problem or just mask a short to ground?

 

I've been working everyday since last Monday, so i haven't had time nor felt like getting out there and working on mine. I already removed the butt splice and have a soldered and heatshrinked 10ga wire from the alternator to the battery. I don't think i ever felt the wire itself to see if it was getting hot after i got rid of the butt splice. I guess i should do that. I'm not going to go that large, but i may go ahead and get a 8ga and a 6ga and see which works better.
I was thinking the same thing. It seems that there is another problem and this may only cover it up. When i fonally get a day off, i'm going to look at the other ground leads/straps and remove them and clean everything up around them to see what that does.
As soon as i get something done, i will post with further results of what i find.

 

I can tell you now, the 6ga will work better since its larger it can handle more. and PurpleHaze I would say the same thing. unless you have an aftermarket alt that generates significantly more than stock you should be fine going with the 6ga. If your alt was producing enough power to require 4ga you would probably have melted through the 10ga long ago.

 

A few days ago I had a 12 GA on there ive had that there for about 2 months, the other day I started to have severe electrical problems ( I had to replacr the coil, ign module, fuel pump relay, and the ecm) I finally got the car running and noticed the wire from the alt to the battery was smoking, so I put on some 10 GA. the reason i ran the wire like that is because i could not get the alt to put out a charge (after tonight I think that may be due to a fuseable link gone bad). Anyhow tonight I put on new negative and positive cables also bought a 4GA wire witht ends on it just in case I needed to go bigger from the alt to the battery. The 10 GA warmed up a bit but it wasnt exactly hot. I just cant see why now i would need anything bigger than 10 GA because isnt that what they ran from the battery to the starter with a 12 GA fusable link? Oh yeah the alt is stock. hopefully i can get the fuseable links repaired this week and see if that is the issue or if they are even burned out. sounds like this may be a common issue?

 

sounds lke you guys need the big three mod, i'm doing it over the winter.

 

WHat is the big three mod.

Also what is this Winter that you speak of?

 

Well, finally had a chance to do something, but not really look for a problem. Today i went in search for some 8ga wire, couldn't find any, so i just went ahead and bought a 4ga lead. I installed it and started the car up to let it run. I decided to put the volt meter to the battery and watch it as it ran to compare it to the dash volt gauge. When i turned the lights on and put it in gear to see if it would what's always done, the dash gauge dropped below 13v and the volt gauge still read about 13.4v. So, that tells me the battery is getting the voltage but the dash gauge is not. Before anyone goes saying i have a bad gauge, why do my lights dim, turn signals slow to a crawl when sitting at idle at a red light at night?

What could possibly be the problem at this point? It seems it has to be something inside the car and not the battery cables themselves. Where does the power go into the car at? I'm at a loss now as to what the problem is.

 

I have the same exact problem. I had the underdrive pullies and it was worse, so I put the stock pullies back on yesterday and it helped but it's still not right. I put in a 4 guage wire from the alt. to the battery like a month ago and that helped too. I also notice that at idle with no lights on, if I hit both window switches at the same time the volts drop to the red zone and I hear what sounds to be the alternator making a whining noise. Before I changed the pullies I tried a new alternator and it didn't make a difference. I also checked my battery with a volt meter and it gets the 13.x volts and also holds those volts when the car is off. I'm puzzled with this as well.

 

Update from me, I changed the batery wires both POS and NEG, and have a 10 GA from the Alt straight to the battery. I wanted to replace the ignition coil and module with some better than stock replacements so I ordered them from jegs, anyhow i did not drive the car for 2 days, went back to start it and the bettery was dead?? Had the battery tested came back bad. This was an Optima Red Top that was 14 months old. I have no clue what the hell is wrong with this thing....

 

i live in ohio, THAT's the winter i speak of.

search "big three" on the electrical board for the other answer

 

Better late then never Reply.

My car had issues charging and wires getting hot. This is something that has to do with all of the wires in the Bundle that is located near the battery.

Basicly ... for some odd reason GM decided to run the wires to a Cluster before going to the Battery.

To fix the Charging Problem, First - get out your ohm resistance meter and see if your getting a short in the wires. touch end to end of the wires, Any Wire Not having .04 to .00 needs to be replaced. If your getting even lower numbers, you may have a short on the Block.. Replace as this could start a fire.

Next... See that big bundle of wires that goes near the front of the car next to where the battery is, and attatched to the back of the Radiator Support. This is all the problems!.

Here GM ran the Alterator to a Distribution Center... Which has all kinds of things... then to the battery.

Check all of those wires from there as if one is bad this will yield the same result. Especailly since this is where your gage voltage comes from.

The easy fix for this problem is to run the Alternator Charging wire directly to the Battery then add another cable from the battery back to the Distribution Area.- This basicly cuts out the middle man.

As long as all your wires are reading .04 to .00 on the Resistance scale everything should be Good, one short causes all this Heat and low voltage scale.

Oh, and Splicing Wires together does not cause wire problems, as long as your going from 12 guage to 12+ guage or Whatever the Wire actually is you should be good (size is not always a good indicator of Guage - as different currents run at differnt speed through differnet metals). No problems from splicing as long as you Heat shirk the ends to avoild Moisture infultration. Sometimes people actually Soldier the wires, but that can be overkill.

 

I always solder all connections.


So far so good.

 

Soldering splices is a good insurance against problems down the road, and is not overkill for high current or weather exposed wiring as it adds conduction area and corrosion protection.. Heat shrink is good but moisture could still creep in.
Some cars (V6?) had a junction block like mjsmikey tries to tell about. It seems to be a source of problems for many.
Apart from that, if you have good voltage at the battery but not inside the car, then inspect the C100 firewall connector. Among other things it passes at least three main current wires going in and out, if I remember correctly.

 

Back from the dead....Any of you get this figured out? Im currently having this issue with my car

 

I once found that it was how my v belt setup that was loose. My alternator had come loose but it still grabbed. The belts didn't squeal as if they were loose and if they did they did it for a few seconds and grabbed and everything looked good except I had a constant low charge. I removed the bolt to the alt and I realized just how slack it was, it had backed up about an inch; enough to cause my then problems. Tightened things up and my charge went back up and my idle improved as well.

Recently, my connection must of gotten iffy since my car would not start over and if it was about to start it would shut my entire car down. Cleaned my contacts and things are back to normal. Try the simple stuff first!

 

I haven't had much time to try to troubleshoot my problem. I've been working so much, the battery has since died and i just don't have the time to work on it right now.

My setup is a serpentine belt and has a new belt. Has had a new alternator as well as battery and still acted the same way. Oh yeah, and new cables for both the pos and neg.

Since the battery has died just sitting there, i'm starting to think i also have a short somewhere. So, once i get some time to work on it, i will be doing to testing for a short. If i do figure it out, i'll post it up. Can't give a time frame though of when i'll have mine done.

 

Please do post up whenever you get around to it. Ive been trouble shooting the same thing with mine.

How did you clean your contacts?