Having a few alternator problems with 86 caprice classic

I am beginning to get frustrated. To give you a little background, I bought the car recently for only $600, the old man who previously owned it and babied it passed away almost 5 yrs ago. His daughter drove it for maybe two years, and then it sat the rest of the time until I bought it. The exterior needs new paint and the top needs to be redone, but the interior is awesome! It is a Brougham edition and has Navy velour interior. It feels like a cadillac. I have had to do some work with it, slowly but surely. I bought it with 86,000 original miles on it and I have put close to 2,000 on it so far and the kinks are letting their presence known. I have had to have a new carb put in, a new radiator and now I replaced the alternator because the voltage regulator was shot and since it sat for that length of time, I just replaced teh whole thing. Probelm is, I am now having problems with the battery draining? I di have to replace my ignition coil as well because after replacing the alternator, I was unable to get the car to start. I am planning to replace the whole cap/rotor/distributor assembly as well. But I am still baffled with this alternator? I have had it tested twice at the parts store and it tests fine, but yet when I use my battery charger which has a built in alternator check, it tells me there is a fault. I have decided that I want to just try another alternator in there, but I have not been able to find the particular model mine is. It looks like the SI series, but the ones I have found online have v-belt pulleys, mine has a serpentine on it. Does anyone know where I can find out the particular one goes in my car? I am looking on-line because you can purchase a new one cheaper than from our local parts stores which only carry the remanufactured ones. Any help or insight will be appreciated. I am stumped.

Well I think there are 2 possibilities here 1st that your alternator is not putting out enough current. At the parts shop are they checking the maximium output with a load tester? Ask them what they are getting for regulated voltage and maximum output

2nd possibility is that you are getting a parisistic drain somewhere in the electrical system this will be more difficult to find you will need a volt meter/amp meter and first check if there is any draw on the batter with everything switched off if there is work from there.

Hi. Glad to hear you like your 86. On my 85, I have to wiggle the electrical connector that plugs into the alt, to get the connection right. Otherwise, it will not charge the battery enough, and the battery light actually will come on.

Once I thought I needed a new alt, because of batteries dying, and the Sears guys said the same thing, but really all I needed was a new fan belt ! Unusual that you would have a serp belt on that 86, I think.



Enjoy your 86 !

As long as you get a Delco Reman unit, you'll be happy. "New" ones are cost prohibitive and I've not had great success with off-brand rebuilds.

Before leaving the store, spin the shaft (it better spin freely/no binding), and have the output tested.


You should have a SI-12 alternator.

If you have a test light, you can check the battery to see if you have a parasitic drain (my theory regarding your problem).

Turn everything off. If you have an underhood light, disable it.

Hook one end of the test light to the positive battery terminal, and the other end to a ground (fender, accessory bracket, etc). If the test light illuminates, you have a drain.

Let us know what happens

I am beginning to get frustrated. To give you a little background, I bought the car recently for only $600, the old man who previously owned it and babied it passed away almost 5 yrs ago. His daughter drove it for maybe two years, and then it sat the rest of the time until I bought it. The exterior needs new paint and the top needs to be redone, but the interior is awesome! It is a Brougham edition and has Navy velour interior. It feels like a cadillac. I have had to do some work with it, slowly but surely. I bought it with 86,000 original miles on it and I have put close to 2,000 on it so far and the kinks are letting their presence known. I have had to have a new carb put in, a new radiator and now I replaced the alternator because the voltage regulator was shot and since it sat for that length of time, I just replaced teh whole thing. Probelm is, I am now having problems with the battery draining? I di have to replace my ignition coil as well because after replacing the alternator, I was unable to get the car to start. I am planning to replace the whole cap/rotor/distributor assembly as well. But I am still baffled with this alternator? I have had it tested twice at the parts store and it tests fine, but yet when I use my battery charger which has a built in alternator check, it tells me there is a fault. I have decided that I want to just try another alternator in there, but I have not been able to find the particular model mine is. It looks like the SI series, but the ones I have found online have v-belt pulleys, mine has a serpentine on it. Does anyone know where I can find out the particular one goes in my car? I am looking on-line because you can purchase a new one cheaper than from our local parts stores which only carry the remanufactured ones. Any help or insight will be appreciated. I am stumped.
It's quite possible there's something draining on there. My husband is an electrician so we'll have to dig out his meters tomorrow and check. My alternator belt isn't necessarily a serpentine belt, it's the serpentine style, that's what I meant. All the ones I've seen on line have the pulleys for v-groove belts. My biggest question is if I do have a drain, what steps do I need to go through to find out what is doing it? If worse comes worse, I do have a friend who is an awesome mechanic, problem is he lives in Daytona Beach, we only see him every few months. My regular mechanic is my best friends father and he only charges his cost for parts and labor, but he's been so swamped right now because of our snowbird season. Worst part is it's also contractor season too, we took the direct hit from Charley here (Punta Gorda/Port Charlotte, FL) and the contractors are here in droves. I can't afford to have my car sit in a shop for longer than two days, it's our only car, unless you want to classify the totalled mustang as transportation...

I didn't think I would like the car at first, I pretty much bought it because I knew it was an awesome deal. You don't find them with that nice of interior and that low miles anymore, especially all original. The old man kept blankets on the seats that were completely sunfaded because he did not want the seats to fade. The interior is beautiful! The only flaw is a few cracks on the dash cover, the rest is like brand new! I will have to get it cleaned up and take some pics. For $600, I feel I stole it. It was a big difference from my 93 mustang hatchback though, it took some getting used to. :)

Well first, let's make sure you're draining. Get the tester out and check.

If you are draining, THEN, leave the circuit tester connected and one at a time, remove a fuse from the fuse panel.

If the circuit tester light goes out, the drain is coming from the circuit you pulled the breaker from.

If it doesn't go out, put the fuse back in and pull another fuse. Sooner or later you're gonna isolate the offending circuit.

Be sure to tell us which circuit is giving you the problem, because it help us narrow down where to look.