: Who's the Biggest Idiot? '81 Coupe deVille Charging Problems

02-11-05, 09:09 PM
Alright, so I can finally start working on the 1981 Coupe Deville I bought for $200.

I got off to somewhat of a bad start though...

I gave the alternator to someone in auto tech at school because the car was having charging problems, and he returned it to me and said it was fine. The only problem was, the little clip that connects to the bottom was missing (and, of course, he didn't remember where he put it), and although I know I can replace it, I don't remember where the wires coming off of it are supposed to go.

Now here's a story about the guy who sold me the car. He replaced the original alternator on the car by himself one day when it quit working. His first mistake was buying an 80 amp alternator for a DeVille de'Elegance, which needs a 100 amp one (I don't know how he failed to notice the rating on the original). His second mistake was connecting the alternator to the battery with 10 guage wire, when it says in big letters on the box that the smallest you should use is 4 guage.

So I assumed that, due to his handwork, that alternator shouldn't be trusted, and replaced it with a Palladium 100 amp one from Advance today.

So, my question is, where do the two wires coming off the clip that plugs into the bottom of the alternator connect to? Also, someone told me that the voltage regulator could also be bad. Is it external on an 81? If so, where is it, and how much would a replacement cost? Sorry if I sound like an idiot, but this is the first car older than 1993 I've touched, and some of the components under the hood baffle me (especially the modulated displacement...)

And, while you're at it, am I the bigger idiot for giving a car part to an auto tech student, or is the guy I bought it from for using the wrong alternator and a wire that's waaaaay too small?

Thanks for your help in advance. I really appreciate it.

- Joe

02-12-05, 12:55 AM
Assuming its something like a standard GM 10SI alternator, one terminal goes to the warning light on the dash (with a resistor wired in parallel generally) and the other goes to a main power distribution block in the car for the voltage sensing function. I believe the warning light terminal is terminal one and the voltage sensing terminal number two as well.

As far as who is the bigger idiot... I'm inclined to say the gentleman you bought the car from. (though, might be slightly biased, being in a technical school. :D )

02-12-05, 11:09 AM
For your regulator question, you can kill two birds with one stone by calling your nearest reputable parts store and ask them for price and availability on the regulator. When they look up your vehichle in their book or computer it will tell them if there is a separate regulator.


02-12-05, 03:01 PM
And, while you're at it, am I the bigger idiot for giving a car part to an auto tech student, or is the guy I bought it from for using the wrong alternator and a wire that's waaaaay too small?

- JoeToo close to call :histeric:

02-12-05, 08:28 PM
Yeah, I figured we were both being pretty stupid, but....

I installed the new one today, after a quick look at the wiring diagrams told me the regulator was internal, and it works fine. The car will actually run for more than five minutes without dying now, and it will start without being jumped. It looks like crap under the hood, but I'll neaten it up in the future, for now I'm just really, really, really excited that it runs, even if the transmission is still too messed up to drive it.

Thanks again everyone.

- Joe

02-13-05, 01:14 AM
Heh, I think I might be able to win a "biggest idiot" contest most days. As an example, today I disconnected the negative battery terminal on my Brougham and as I was loosening the bolt I touched the wrench to the positive terminal. Sparks galore! Truthfully I shouldn't be allowed in the engine compartment and yet... I can't help myself!

02-14-05, 09:50 AM
Okay, so I noticed last night that when the engine is running the "no charge" light will come on very faintly and then, after about ten seconds (or until I give it gas), go out on its own. Is this possibly something I need to address, or can I just ignore it? Personally, I think the engine is idling too slowly and the alternator is not generating at the level it needs to be.

On the plus side though, it sounds a whole lot better than I thought it would. Maybe it won't be as hard to get up and running as I first thought...

I plan to take it out for the first time this weekend. I'll post some pictures when I do, but it's in the dirty carport right now and its suroundings don't exactly do it justice.

- Joe