fabgmc4me

iTrader: (5)

Last week I noticed my “Check Gauges” light was flickering on and off and at the same time my voltmeter was bouncing up and down from about 13.5 volts to maybe 11 volts (about where the orange starts). So I first thought it was probably the alternator, but wanted to check a few other things before just throwing a new alternator on there. So I checked the out put voltage of the battery, checked the battery connections, and they seemed good. So I went to autozone to have the check my alternator. It put out around 13 amps, and the autozone said it should be putting out about 102 amps. So I just thought that was the problem. Got the new alternator and installed it, and installed a new battery (old one was ok, but 5 years old) at the same time. Installed new battery posts too, and cleaned all the connections very good.

So I was still having the same issue. It doesn’t happen 100% of the time, but very often, maybe 80% of the time. So I removed all the grounds that are visible from the top of the engine bay, cleaned all of them, and reconnected them.

Still having the issue. I read in another post on here, that a persons MAF sensor was causing a similar issue. So I took the MAF off my other Formula, and installed it, just to eliminate that as an issue. Still having the issue.


Does anyone have any suggestions of what it might be? Or what I can try next to possible fix the issue.

Thanks in advance
Nick

Thebeast431

iTrader: (2)

I would suspect another bad alternator. If you got a remanufactured one it could be the culprit. They come bad out of the box on occasion. Do you have an aftermarket stereo installed?

Travis

ultraz

iTrader: (4)

cross fingers and hope its not ur ECU.

fabgmc4me

iTrader: (5)

I do have an aftermarket stereo, but I had disconnected it, to eliminate that as part of the problem. The stereo is very small, just an amp to power my speakers, no subs.

staringback05

iTrader: (8)

check your power wires to the fuses, starter, battery and alternator....sometimes problems can arise from wires melting or crossing....giving similiar results to your problem

Mike44138

iTrader: (3)

If you had a bad ground (especially negative bat cable) it's likely that it fried the diodes in the old alternator. If you did have a bad ground and ran the new alternator before correcting the problem it's likely fried now too.

waiting2bl33d

go get your old one tested before you spend the cash.

fabgmc4me

iTrader: (5)

Last night I replaced Main positive harness, and the main negative harness. (the ones that attach from the battery to the starter, alternator, block, fuse distribution, ect.)

Car was still having the same issues.

So today I'm pulling out the new alternator I just installed from Autozone, and going to have them replace it, and install the new one. Hope this works. Or else I have no idea what it could possibly be.

fuseone

are you using a dvm to check any thing?

fabgmc4me

iTrader: (5)

Installed the new alternator today around 5pm. Started the car, and the voltage was fine (happened before too, then got bad after a while). Started driving the car for a bit, and seemed fine. About 14.5 volts while driving, and 13.2 at idle. Drove the car for about 30 miles, with a few stops in between, and eveything seemed OK.

Then i get on it a bit, and the ses light comes on, and the volts instantly drop to where the orange starts on the gauge. So I got to my buddies house, and parked it. Later went to go home, and started it up. Was still ot the top of the orange. So I figure I'll try to make it home, what the hell. Start driving and the volts start to drop consitantly as I drive, the car ended up dying just as I pulled into the driveway.

The only thing I can think is that it has to do with the connector that plugs into the top of the alternator.

Any ideas? What exactly does that wire do, and where does it go?

Havok2

iTrader: (118)

that connector should have 1 wire only. and make sure it clicks in.
and you said your SES light came on, what code is it?

when my alternator went out, my ses light didnt come on, but my check gauges light did.

staringback05

iTrader: (8)

check your wires.....

fabgmc4me

iTrader: (5)

Low voltage to my O2 sensors was the ses code.


I've checked every wire, except the exciter wire. I made sure it wasn't broke from the connector, and made sure it was pluged in, but I'm going to make sure now the connection is good. Make sure the pin is making contact inside the conector.

fabgmc4me

iTrader: (5)

What wires specificly are you refering to? I've already checked or replaced just about everything.

staringback05

iTrader: (8)

starter wires, fuse wires,....i know youve already checked your battery wires...if these all check out, check some of the main sensor wires around the engine bay for load....i had a maf issue one time where a bare maf power wire was touching another, thus throwing my voltage all over the place....

fabgmc4me

iTrader: (5)

Just to make sure it wasn't just a bad connection on the exciter wire, I got a new plug from the dealer, and spliced in on, and connected it to the alternator.

Still didn't fix the issue.

I want to check to see if the alternator is getting a signal from the exciter wire.

Is there a way I can test this, like hooking up a multimeter to it, and seeing a specifc voltage. I just want to make sure the alternator is getting a signal from the exciter wire. Any info would be appreciated.

Thanks in advance.

fabgmc4me

iTrader: (5)

Tonight I checked the exciter wire. It was getting a 12v signal when the car was keyed on.

I also spliced in a extra connector and ran a direct 12v to the plug on the top of the alternator to trick it into charging. It still wouldn't charge. With the car running and the exciter wire attached, I checked the voltage output directly at the alternator, and it was 9v or so.

So I'm assuming that this alternator is bad also, that would make 2 Autozone ones in a row bad, even though they both tested good on autozones test station.

I'm going to get a Actual AC Delco one and install that. Hopefully that fixes all my issues. If not I'm completely lost and out of ideas.

Mike44138

iTrader: (3)

All you're going to do is end up smoking another alternator. You've got a wiring problem somewhere. I still think you've got a bad ground or a short to ground somewhere. Don't think this would matter, but has the battery been replaced recently or have you had it load tested? Do you have any other wierd electrical problems or blown fuses?

fabgmc4me

iTrader: (5)

Yes it is a brand new battery. I also tried another good battery as a test also. I have checked and cleaned just about every possible ground on the car, all the major ones for sure. I checked every fuse in the car, both under the hood, and inside the car, and none of them are blown.

Mike44138

iTrader: (3)

Next thing I would do is pull the battery cables off and test the hot lines at the alternator and fusible links for continuity to ground. If you see any abnormally low readings I'd investigate the wiring.