hey guys i just got an 83 camaro and its got an 87 trans am carbed 350 on it. im a pretty good mechanic i work and build everything on my own but this one if throwing me for a loop. here i am on my fifth alternator and still have the same problem. i got the belts adjusted right and it keeps happening. when the cqar is on, even at idle, it makes an absolutely terrbile screeching noise. it has a brand new belt and im sure its not that. ive checked all the other belts and they dont squeak only the alternator. but here is the catch: when i unplug the two wires leading into the voltage regulator, it goes away, belt still spinning. what would cause it to squeak only when the voltage regulator is plugged in? thanks ahead for your help it is greatly appreciated!

 

Need to answer you with a bunch of questions first.
Is your belt setup stock or custom?
V-belt or serpentine?
Has anything else in your electrical system been acting up at all?
What voltage does your dash gauge read?
Have you checked voltage output at the alternator with a meter?
Do your headlights get brighter and dimmer when you rev the engine up and down?

For some reason, your belt is squealing due to the alternator being under a load. You're sure the belt is absolutely tight?
When you unplug the regulator, the alternator is just free-wheeling, not putting out a charge, and not under a load.
That's why it quiets down when you unplug it.

You can test the voltage regulator to see if that's the problem.
Look at the back side of the alternator, adjacent to the voltage regulator (the plug attaches to the regulator).
You will see the back of the regulator (shiny metal) through an opening in the alternator case.
Take a small screw driver and touch the tip to the back of the regulator, and also touch the screwdriver shaft to the alternator case.
That will ground out the regulator and put the alternator into "full charge" mode. And don't worry, you won't get zapped!
When you do this, you should hear the alternator really whine as it's putting out a heavy charge.
You only need to ground the regulator momentarily to see what it does. And you won't be hurting anything else in the electrical system either.
If the alternator makes no difference in sound when you ground it out, then that would indicate that your voltage regulator is already working overtime.
Then you have to find out why the regulator isn't "regulating", such as some other problem in your charging system, wiring, etc.
Unless you're just getting crappy alternators??? But five bad ones is a lot.

 

i have the stock belt setup i believe at least it is how it is when i got the car. it is a v belt setup as well. my battery gauge inside is reading right around 10 volts. i cant imagine the regulator is going back because they are all internally regulated, so each new alternator will have a new regulator as well. everything else in the electrical system is being weird as well because of the alternator. the battery only holds a charge for so long and then it dies (brand new battery) it almost as if the alternator isnt putting anything out at all. i have been throwing the battery on the charger at night, it reads about 12.5 on the gauge and then i keep driving and after a while it is dead again and wont start. what do the two wires from the regular lead to? maybe one of them is grounding out or crossed backwards or soemthing? is that a possibilty?

 

I don't see the wires to the regulator getting crossed, the plug only goes in one way. Check to make sure the "hot" output wire (separate fatter wire) on the alternator isn't shorting out anywhere. It can be close to the valve cover, so make sure it isn't touching any metal. Reading ten volts in the car isn't what it should be, obviously. You need to check voltage output at the alternator on the output wire to see if it's charging correctly. If it is, then it sounds like you have a short somewhere else in the system.

 

i know i jsut had some wires repaired now that i think about. a rat got into my wiring and i paid to have it fixed. i wonder is possible they got hooked up beackwards or soemthing when they were spliced back together. does anyone know where those two wires lead to? as far as i can see they go into a big harness and i couldnt follow them any further

 

Look up a wire diagram at autozone.com in the repair section. Check continuity between the battery and the alt? When its running is there any voltage going to the battery or is it the 12.5 or less? There may be a fuseable link in the harness from the battery to the alt that may be burned inside. The wire is suposed to burn away but at times it gets funky inside the round plastic connector. Also there is a volatge sensing fuseable link on the starter with some others. Check them as well. Vermin may have gotten to them as well.

 

i ran a brand new wire from the alt to the battery with no fuse so that shouldnt be a problem. i will have to checka ll of the wires i traced em as far as i could and didnt see any cuts or breaks in any of them.

 

I have a similar problem that's driving me crazy. I have an 84 Z that charges okay when cold, but after it warms up and you turn on lights, heater, etc it drops down to charge at around 10V. I'm only on my third alternator. Replaced fusible links down by starter, plug wires, disty cap and coil, battery, and even ECM. Nothing seems to make a difference.