alternator or what problems???

**firebird71** · 09-26-2011, 05:58 PM

Had a problem last night with my 04 GTO, coming home from eating last night.
Turned onto the interstate and my ABS light came on thought HMMM ok maybe a wheel sensor is bad kept on driving and battery light came on then went off, then the radio went off then came back on, now the car is running fine engine is running like it always does headlights are on so are the tail lights.
further we went more shit started going crazy inside, speedo would go to zero then back up to where it should then back to zero..
Got it home finally and check the voltage and the voltage read about 9v according to my digital gauge pod in the car..killed it and that was it nothing put a battery charger on it and it started to charging after about and hr it read 11.5v and started the car cranked up just fine no problems at all no lights radio worked no ABS lights nothing working fine but the voltage stayed at 11.5v. left it on charge all night got up this morning charger off and it read 12.3v didn't have time to mess with it to crank it before work.
got home tonight gauge read 12.2v cranked it and it cranked fine but stayed at 12.1v after about a minute it kinda started climbing went to 13.1 then dropped to 12.1v and thats it no more ran the car for about 5 min and it dropped to about 11.5v.
suggestions, thoughts, opinions?
me i'm thinking alternator, but it could be something else so thats why i'm asking.
thanks, Charles

**35th-ANV-SS** · 09-26-2011, 06:06 PM

From the things you've just described, I would also guess alternator. Did you look at all of the connections to make sure they were intact? How about the battery terminals? Clean?

**firebird71** · 09-27-2011, 04:46 AM

Terminals r clean and in good shape. Connections are tight. I'm just hoping it's not the voltage regulator which is
In the computer isn't it?

**cammed goat** · 09-27-2011, 12:52 PM

I don't know as I have never heard of any late-model GM having an external voltage regulator. You checked your belts, correct? I only ask as it almost sounds like a tensioner might be on its way out. Or there is a bad ground somewhere.

**smokestack** · 09-27-2011, 01:39 PM

If not a ground wire....have the battery load tested. Its gonna die soon.

**zerbe's99ws6** · 09-27-2011, 04:53 PM

a quick test for alt. start eng. disconet battery pos. term. if alt is working the car will stay running also check your gage you should have 13 to 14 volts with battery disconecked. also do have battery load tested. if you donot have atleast 13 replace the alt.

**cammed goat** · 09-27-2011, 06:54 PM

I would advise against disconnecting the battery while the engine is running. OP will most likely need a new ECM if he does that. Voltage spikes are NOT good.