my car is screwed up!

It is actually more common than it should be to get a faulty alt. First of all, check with a voltmeter to make sure that your guage isn't lying. I'm sure it's not as the car is dying. Don't bother digging around under the hood for the voltage regulator - it's internal on your car, meaning it's inside the alternator. The post that the little single red (usually red) wire at the back of it hooks to is the connection to it.  (Edit:  Oh wait. in '86 you could have either the white 2 wire connector on the side with the little red wire on back, or a 4 or 5 wire on the side only in a GM Weatherpak connector.)  I would take it back to Auto Zone again and haave them check it again, along with your battery. Yeah, they'll probably be getting sick of seeing you, but one of these is more than likely your problem. There isn't muck else in your car that could possibly cause enough of a draw to kill the car.

As said before, check your engine to body and frame grounds. There should be a flat braided steel cable connecting the engine to either body (firewall??) or a framerail. If you absolutely can't find anything that looks like just a ground wire, it wouldn't hurt to add in your own. Just clean it up real good around a couple of bolts.

I think that the thermostat was just an amazing coincidence, as there is nothing electrical about them. Unless some of the boiling over anti'freeze may have gotten into the alternator.....

As far as the belt tensioner, it is not adjustable. Either it is working within specs. or it should be replaced. It is a spring loaded mechanism. I'm not sure what the exact specs. are for your car, but you can use your judgement pretty good if there is enough tension on it. The belt itself could also be bad...  or wet?....

Hope this helps.

They're around, but are usually the type you wish you hadn't asked for after they begin...

If you want to know how to test your alternator, don't do the disconnect battery test. It's a bad habbit and can ruin some cars.

Connect the black  (negative) lead of you DMM to anything with ground potential. The motor or frame or even the negative battery terminal is fine.

Check the positive terminal with the red (positive) lead of the DMM. Check the voltage on the positive connection at the alternator. A good reading should be 12.9/12.6v , higher reading being at the alternator with engine running. A similar voltage drop, .3 or whatever shows the alternator is charging. If you get 12v with the engine ground and alt, but not with the frame/batt ground and alt...this would indicate a bad ground.

Autozone is a great parts store, but it's not uncommon to get some bad luck with some parts, especially alternators. It's happened to me before....just bring it back. Most GMers recomend the rebuilt AC Delco aternators. I had an autozone one in my T/A which lasted years, your's may just be a bum unit.

True, but there is still a slim (i agree - very slim) chance. It is always recommended to cover the alt. if you wash your engine. And can you imagine the look on the guys face at autozone when you bring one in for warrenty with antifreeze dripping out?

Dude, just pull out the alt. and battery, have someone give you a ride to autozone, and have them tested. I'll bet you a dime on the dollar one of the two is bad.

Good luck.

With the lights working but the car not starting.....that sounds like a definite bad ground to me.

The dash lights doing wierd things and other symtoms really point to a bad ground.

The ground isn't hiding from you, infact if you can't find it.....make new ones.

Buy assembles cables from the store, one with a battery clamp on one end and a lug on the other. Bolt it to the frame of the car. Buy another wire with the lugs on both ends, bolt one end to the motor/transaxle and botl the other at the same place where you bolted the other one. Clean the frame connection real good, get it down to bare metal in the area where the lugs connect, use a star washer and clean the threads very well too.  Apply some di-electric grease to all of your connections to keep the corrosion away.

Chances are, you will find your factory grounds while doing this, leave them in or rip'em out...your choice. As long as you replace what you take off. Most motors have a smaller ground connection on the opposite side, you may find more than one...just clean those connections too. 

Use wire as thick as or thicker than the factory ground wiring. (lower numerical gauge size). With a car like that 4 awg will do.

Have the alternator and battery checked again while you're at it.

Ditching a car over electrical problems? No way...don't give in that easilly.....unless you want to give it to me! Is the motor and trans solid?