Alternator not charging?

[AllZWay]

At TWS, my alternator decided to stop charging and had to charge my battery after every race. (BTW...Thanks to Mitch and Jeff B for loaning me their chargers.)

I have taken the alternator to O'Reilly's and it tested good. I have tried another alternator (unproven good), but I still can't get an alternator to charge.

I thought it might be my master cut off switch and tried to just wire around it, but no luck.

I changed dash clusters, since with the stock dash cluster the alternator is wired through it.

The alternator appears to not be putting out anything and have worked two days chasing wiring and don't find any problems.

Any ideas of what to check now or test I could try?

[evarner]

Not sure about GM products, but is the voltage regulator built-in with the alternator or does it use a separate one?

[AllZWay]

Not sure about GM products, but is the voltage regulator built-in with the alternator or does it use an separate one?

It is built in and the dash cluster actually has a resistor that the alternator sinces to allow the exciter to turn on.

I am considering to just getting a new alternator and check it. I am not sure I trust the guy at Oreilly's testing.

[David Love AI27]

Not sure about GM products, but is the voltage regulator built-in with the alternator or does it use an separate one?

It is built in and the dash cluster actually has a resistor that the alternator sinces to allow the exciter to turn on.

I am considering to just getting a new alternator and check it. I am not sure I trust the guy at Oreilly's testing.

ask to see the test... should put out @ 14 volts and 40+ amps (amp spec used to be stamped on the alt)

[AI#97]

alternators can test good on the stand because the field circuit is powered. I watched a lemons team spend 16 hours trying to figure out a similar problem. Turned out the circuit that powered the field (ie, turned on the alternator to charge) had the fuse removed.

Think of it as a 12V source that turns on the alternator. Don't know if the 4th gens are wired the same way, but most every car I have seen that has an internal regulator is wired this same way. I am betting that field circuit is either damaged, burned or has a blown fuse. LAW should be able to confirm in 10 seconds or less.

[Alien]

Been stuck in Waco because the field wire had a break in it. Alt just wasn't getting the signal to start charging. Once we figured that out, I would start the car, jump from the hot on the alt to where the field wire attached and the alt would do its job.

[Al Fernandez]

Call Mitch, this is the exact same thing he went through recently.

[AllZWay]

I went to all the local auto parts yesterday and was going to buy a replacement one, but none carry them in stock. :evil:

[GlennCMC70]

check for 12v at the small wire on the plug onthe bottom side of the alt. if it doesnt have 12v, the alt will not put out anything.

[AllZWay]

check for 12v at the small wire on the plug onthe bottom side of the alt. if it doesnt have 12v, the alt will not put out anything.

I wasn't sure what the voltage was supposed to be, but I was getting 12 volts there.

I am really thinking it a bad alternator, despite what O'Reilly's says.

[jeffburch]

Vatazone has testers aswell.
jb

[AllZWay]

Vatazone has testers aswell.
jb

They said they didn't have what they needed to test it. They put it on their little machine and then said..."we can't do it. "

[jeffburch]

Hmm, so I'm guess there's only one store in town huh? :)
jb