Alternator problem?

[IsLegend9]

So I was driving the good ol' '81 GL down the highway today, and my gas gauge was getting low. Right as the light came on, the car turned off. My first thought is, alright, I must've missed the light come on before and that was it. Then I remembered that when I started it about 15 minutes before that, the accessory lights [the ones that come on right when you start the car, that show all the door lights and the parking brake and such on the little diagram of the car on the dash] as well as the battery light on the voltmeter stayed on for quite a long time longer. I manage to start the car again, and the lights stay on, and I make it maybe 300 feet before the engine turns off. So, I get my dad to bring me some gas and see if that's the problem, and the same thing happens again - the car turns on, the engine turns over and such... and then it stops. Those lights never turn off. And the voltmeter never goes right up to 14/16 and stays there - it wavers very strongly around the 12 volt marking before it turns off.

 

Any ideas on what the problem could be? Alternator initially comes to mind. Maybe a cell is going in the battery?

 

Any thoughts or tests to try would be great. Thanks guys.

[Indrid cold]

agree.. probably alt or battery... a bad battery makes these roos do funny things and both are easily tested.

[GeneralDisorder]

I emailed your dad a reply to his question on the issue so check with him - but also I will note for further discussion by board members here that being an '81 your's will have the external voltage regulator so it could be that and not the alt itself.

 

GD

[IsLegend9]

Thanks so far, guys. We've got a voltage regulator on the way here - since it was only $25 or so, even if it isn't the problem, it'll be good to have. I might try to convince my dad to get a new battery today, just in case. I'll post again once we do a little diagnostics later today.

[Indrid cold]

I emailed your dad a reply to his question on the issue so check with him - but also I will note for further discussion by board members here that being an '81 your's will have the external voltage regulator so it could be that and not the alt itself.

 

GD

 

ahhhh....! External reg... G.D., appreciate the correction and info.

[gadberry]

I had a similar dash warning/Low voltage light (and output) appear on my '81 wagon

this last Saturday as I was out for a ride. Had it checked for

free at two local auto parts stores just to see if they both id'd the

same part... It was a toss up between the external volt regulator

and the alternator... Alternator was about 2-3 yrs old but I replaced

it since it was $30 for a reman from Mexico... That was my problem

so guess they don't make'em like they used to yo..

 

Decided to complete a tuneup while I was at it..

 

Good luck

gadberry

 

 

Thanks so far, guys. We've got a voltage regulator on the way here - since it was only $25 or so, even if it isn't the problem, it'll be good to have. I might try to convince my dad to get a new battery today, just in case. I'll post again once we do a little diagnostics later today.