Forget the hammer, call in an exorcist!

 

Can I get an amen! I'd love to watch someone with tons of knowledge dive into this thing. It's gonna come down to 1 wire somewhere I just know it. But where!!!! Is there a bare wire somewhere touching something? Is there a ground loose somehwere? Is it a bad alternator? I can't think of anything that I've overlooked. It was ridiculous that it wasn't fixed at the end of August last summer! If I was to take this thing in to have it looked at I'd pay hundreds of dollars to have them look at the same things that I already have. I'm gonna need depression meds before this is over.

 

Ok...My two cents here. Have you had this battery deep charged since all of this happened. Jumping it doesn't charge it and running for the short times described won't either. It seems to me that 12.3 volts on the battery is too low. Your alt. is struggling to bring a discharged battery up to full charge as well as keep the acc. going. Have you replaced all of the ground wires/straps, or at least cleaned all of the connections, pos. and neg.?
The overheating of your alt seems like a belt/pulley issue since it's hot on the pulley not the case. Is there a chance it's too tight, causing the bearing to be stressed and overheat? I know you've said it's not slipping, but the symptoms you describe suggest a slippage(amps decreasing on engine rev).
Anyways, my two cents...good luck.

 

I put a brand new battery in the car and it drained the charge in 1 day. I see your point about not running the car long enough to charge the battery. I did drive the car yesterday almost 30 miles. As soon as I turn headlights on and drive for about 2-3 miles the voltage gets so low that all the lights no longer work. I have replaced all cables and checked all the grounds many times. There's are some bizarre things happening with this that I can't figure out. The car runs fine (and restarts) if I don't use the accessories. If I turn the headlights on it only takes minutes and the voltage drops to nothing and lights stop working and the car won't restart. I've driven the car for 2 days now without any accessories with no problems. The only time I see 14+ volts is after I jumpstart it and let it idle at 1500 rpms. As soon as I hit the gas to bring the revs down, the voltage output goes down to around 13.
If anything, the belt could possibly be too tight, it's definitely not loose and slipping. The alternator does get extremely hot on the case also after running/driving for longer than a few minutes/miles. The pulley gets hot first after running for 2 minutes - literally. I am curious however if it's possible that the pulley is too small for the belt. It's a standard v belt (very recently replaced) and it fits into the pulley but doesn't seem to go all the way in? The belt is not flush with the pulley but I have checked it for slipping so many times, like I mentioned if anything, it's possibly too tight and I'll try adjusting a bit tonight. The amps don't always decrease on revs, only when the lights were on and everything is about dead. You made some good points and I really appreciate it! I've checked and/or replaced everything that could be a "normal" issue with an alternator. I'm going to try again with the headlights this evening (before it gets dark this time) and see what happens. Thanks again.

 

Had the same problems again last evening when the headlights were on. I took your suggestions Rjtack and went out and bought a new charger and brought the battery up to a full charge. When I start the car the alternator is putting out 13.1 volts. As soon as the accessories are on the voltage starts to drop and doesn't recover. Forgive the ignorance but wondered if something like a bad ground on the headlights could be causing this problem? I just don't understand why the alternator isn't delivering sufficient voltage? Really starting to think this alternator has been damaged internally from whatever was going on. Don't know what else it could be. All wires in the engine compartment have been inspected and replaced if there was anything wrong with it. New battery cables and I replaced the ground from the starter to the frame last night as well. Could a shorted wire under the dash or somewhere else in the back end be causing the alternator to do this?

 

I finally got the new alternator back from Summit today (alternator #4) after a LONG wait. Having checked and or replaced every wire/cable/ground strap that I could possibly think of per the numerous prior posts I was really hoping for the best. Needless to say I waited weeks for a new alternator for nothing. Didn't fix a (insert any number of expletives here) thing! I really don't want to even ask what it could be at this point. Maybe I will yank the heater out and just buy a couple of rechargeable spotlights and mount 'em on the fenders? Car works fine with no accessories.

 

I know im new here and all but you might be grounding your postive battery cable out on your engine block Im not sure if you have a original engine or a big block but I know with my big block I had a similar isssue with it the postive battery cable twisted and touched the engine when hot and was causing it not to start when hot. Or you might be getting heat transfer into the starter causing it not to want to start. just throwing it out there.

 

I really appreciate the suggestion 468, I have checked and replaced the battery cables even though the positive cable was fine. This problem has haunted me for the last 13 months and I still have yet to solve it. 4 alternators, new starter, battery, cables, wiring from bulkhead to starter, upgraded 4 gauge wire from alt. to battery, new ground cable from starter to frame, new belts, new medication etc. etc. I am NOT one to give up on issues but this has me just shy of insanity.

Where the problem stands right now is the car will start and run fine (with alt. showing 12.8 volts) without any accessories on. Within 30 seconds of running, the pulley and fan on the alternator is ridiculously hot. That would indicate alignment and/or belt slippage issues for most normal circumstances. I've tried countless times to realign the alternator with spacers and or without and still it's too hot to touch after 30 seconds or less. As far as charging goes, everything I've seen or read says a grounding or connection issue. With one wire and everything being brand new and checked so many times, I'm left wondering about grounding. I would love to find out from anybody how many and where the best grounding points should be? That's literally the last thing that I could try that I know of.

 

Hey 78...You mentioned in an earlier post that you found green dust on the ground cable at the battery. Did you ever replace that cable, or just the batt terminal? That is corrosion and WILL cause a high resistance situation. Think about it, if I was corroded at the batt end, it will be corroded at the other end. That factory crimped end at the Alt. bracket is probably not getting a good contact with the wires inside due to the 'green dust'. If any of your other cables are in that condition that will contribute to your issue. Also, on a more obscure note, any chance the alt is spinning backwards? I know it sounds crazy but there are GM alt. that are designed to spin in the opposite direction. It'll still produce volage, but not as much and it will overheat due to the fins not pulling air into the alt to cool it. Old corvette comes to mind. Just spitballing there.

 

You've got a drain on the system before you turn anything else on, and once you turn on lights, or any heavy load it's even worse. The drain is causing your alternator to run hot and that's why you have the heat issue with alt. and belts, plus the 12.8v. reading. My alternator runs at 13.8v. unloaded with nothing on, and doesn't drop but a few tenths when I switch anything on.
Take your car to an auto electric place and have them put a DC amp meter on the main alt. lead and they can tell you what kind of amperage it's pulling with nothing on but the engine, and also with accessories on. There's a short somewhere that's ahead of any of the accessories, and the accessories just make things worse. You'll wipe out the new alternator if it isn't found, and the battery too.