Addicted To Boost Posted March 23, 2009 Report Share Posted March 23, 2009 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? Quote Link to comment Share on other sites More sharing options...
White93z34 Posted March 23, 2009 Report Share Posted March 23, 2009 fusible link? get old and new alternator tested? battery test good? Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 23, 2009 Author Report Share Posted March 23, 2009 The battery is 2 months old as well. Where is the fusible link? Quote Link to comment Share on other sites More sharing options...
White93z34 Posted March 23, 2009 Report Share Posted March 23, 2009 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. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 23, 2009 Author Report Share Posted March 23, 2009 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 Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 BUMP Quote Link to comment Share on other sites More sharing options...
AL Posted March 24, 2009 Report Share Posted March 24, 2009 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 Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 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? Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 And Al, I believe the voltage regulators are built into the alternators, correct me if I'm wrong. Quote Link to comment Share on other sites More sharing options...
jman093 Posted March 24, 2009 Report Share Posted March 24, 2009 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. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 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. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 I'm getting 9.90 volts at the battery. Quote Link to comment Share on other sites More sharing options...
jman093 Posted March 24, 2009 Report Share Posted March 24, 2009 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. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 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? Quote Link to comment Share on other sites More sharing options...
jman093 Posted March 24, 2009 Report Share Posted March 24, 2009 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. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 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. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 Any ideas of what may be causing this? Quote Link to comment Share on other sites More sharing options...
jman093 Posted March 24, 2009 Report Share Posted March 24, 2009 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 Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 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". Quote Link to comment Share on other sites More sharing options...
88red4cyl Posted March 24, 2009 Report Share Posted March 24, 2009 Are all the cables/grounds clean and tight? Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 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? Quote Link to comment Share on other sites More sharing options...
AL Posted March 24, 2009 Report Share Posted March 24, 2009 Sounds like something isnt getting a good connection How clean are your battery cables/posts/connections Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted March 24, 2009 Author Report Share Posted March 24, 2009 They look just fine, they aren't rusty, and I re-tightened all connections. Quote Link to comment Share on other sites More sharing options...
AL Posted March 24, 2009 Report Share Posted March 24, 2009 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 Quote Link to comment Share on other sites More sharing options...
rockfangd Posted March 24, 2009 Report Share Posted March 24, 2009 sounds like a fusible link to me Quote Link to comment Share on other sites More sharing options...
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