GP Not Charging.... FIXED!!!

[Addicted To Boost]

Alright, so I was driving the GP yesterday and it showed the symptoms that the alternator had died, and the volt gauge steadily fell all the way home.

 

This morning, I went out and bought a new alternator and put it in, and it is still not charging.. my volt gauge is sitting at 8 volts and the car is idling at 2k...

 

What could be the issue here?

[White93z34]

fusible link? get old and new alternator tested? battery test good?

[Addicted To Boost]

The battery is 2 months old as well. Where is the fusible link?

[White93z34]

that does not necessarily mean anything.

 

the fusible links are right by the starter, it is rather unlikely those are shot as the car has never seen any salt, and unless you shorted the battery.

 

 

[Addicted To Boost]

I had the old alt tested just now and it checked out good, so I traded the new alt back for the old one and got my money back. Old alt is back in the car.

 

Could they have possibly been shorted out when we were flushing the cooling system yesterday? My buddy was scrubbing the engine while we had the water running..

 

Have a pic what these links look like? I've never dealt with them before.

 

Thanks

[Addicted To Boost]

BUMP

[AL]

There should be a red wire going from your alternator to your battery which is what charges it... Somewhere along that wire I think is some sort of resistor or similar to make sure the alt doesnt overcharge the battery, That could be not letting current through... I will research what I am talking about and post again

[Addicted To Boost]

On my TGP, I bypassed the factory charge wire when I had my alt internals replaced with 200 AMP internals, I just ran some lower gauge wire from the alt to the battery.. Do you think running a new wire to the battery would fix the issue?

[Addicted To Boost]

And Al, I believe the voltage regulators are built into the alternators, correct me if I'm wrong.

[jman093]

You are correct, GM alternators on our cars control voltage internally. I think the problem is with your gauge. If it really had eight volts you likely couldn't have started it, may have had a check engine light, it may have run bad, and if you have ABS, the ABS light would have been on (the EBCM sets a fault if it receives less than 10.8 volts).

 

The reason it's idling high is because disconnecting the battery when you changed the alternator wiped the computers memory clean. Idle control is one of the things kept in it's memory. At work we relearn them immediately with the Tech 1 or Tech 2, but you can relearn it just by driving it like normal. It will eventually relearn itself. It usually takes just a couple trips, but sometimes for whatever reason they may take a couple weeks. OBD1 isn't very sophisticated. Hell, my Lumina took like a month without the Tech 2, not sure why, but yours probably won't take nearly that long.

 

Here's what you need to do to start. Get a voltmeter and stick in on the battery posts with the car running. Should have 13-15 volts. If it does your charging system is working fine.

[Addicted To Boost]

You are correct, GM alternators on our cars control voltage internally. I think the problem is with your gauge. If it really had eight volts you likely couldn't have started it, may have had a check engine light, it may have run bad, and if you have ABS, the ABS light would have been on (the EBCM sets a fault if it receives less than 10.8 volts).

 

The reason it's idling high is because disconnecting the battery when you changed the alternator wiped the computers memory clean. Idle control is one of the things kept in it's memory. At work we relearn them immediately with the Tech 1 or Tech 2, but you can relearn it just by driving it like normal. It will eventually relearn itself. It usually takes just a couple trips, but sometimes for whatever reason they may take a couple weeks. OBD1 isn't very sophisticated. Hell, my Lumina took like a month without the Tech 2, not sure why, but yours probably won't take nearly that long.

 

Here's what you need to do to start. Get a voltmeter and stick in on the battery posts with the car running. Should have 13-15 volts. If it does your charging system is working fine.

No, it won't start on its own. I have to jump the car with my truck and it will run worse and worse as the gauge drops lower and lower. The check engine light comes on while it is running and all lights are very dim. I'll check the battery right now with my multimeter.

 

[Addicted To Boost]

I'm getting 9.90 volts at the battery.

[jman093]

Ok sorry, well then you are having charging problems. Didn't know you were having those problems. Then with the voltmeter out, also put one probe on the negative battery terminal (or any other good ground, make sure it's good though) and put another on the stud on the alternator that attaches big battery wire. See if there is good voltage there. Again with car running.

[Addicted To Boost]

Alright, I'll do that. I want to test the alt charge wire for continuity as well, where do I place my leads to test that wire for continuity?

[jman093]

Alright, I'll do that. I want to test the alt charge wire for continuity as well, where do I place my leads to test that wire for continuity?

 

That's what you're doing by checking the voltage at the alternator and comparing to the voltage at the battery. You cannot properly check continuity by checking ohms resistance. Think of it this way, if every strand of wire in that battery cable was broken except for one of them, would it have continuity? Well yes, and you would measure close to 0 ohms on the meter, but is it going charge? No. That one strand can provide the current flow for the meter, but not the vehicle's charging system. Not an accurate test. So in this case you have to test with available voltage and compare.

[Addicted To Boost]

I jumped the car, and I was getting 9.00V at the alternator, and steadily dropping by .01V. I got the same reading from the battery as well.

[Addicted To Boost]

Any ideas of what may be causing this?

[jman093]

Sounds to me like the alternator is bad if there's only nine volts at the alternator terminal. But another didn't fix it? I dunno then

[Addicted To Boost]

Yeah I put in a brand new alternator this morning, and it did the same thing.. so I returned it and my alternator bench tested "good".

 

[88red4cyl]

Are all the cables/grounds clean and tight?

[Addicted To Boost]

Yeah the cables are tight, aux post is tight, charge cable is tight.

 

This is an Arizona car, so everything is as CLEAN and rust/corrosion free as a new car.

 

The car has had one intermittent issue since I picked it up though..

 

Sometimes when I turn the key, all I hear is a loud click, and I have to let off the key and turn it again and it will start. Sometimes I have to turn the key up to 4 times before the starter engages instead of making the loud click.. Related issue or just a bad starter?

[AL]

Sounds like something isnt getting a good connection

 

How clean are your battery cables/posts/connections

[Addicted To Boost]

They look just fine, they aren't rusty, and I re-tightened all connections.

[AL]

Pick up some battery cleaner and clean the posts with a toothbrush... Also scrub the cable part that connects to the battery... I have seen bad connections do crazy things

[rockfangd]

sounds like a fusible link to me