Alternator Head Light Drain 76 Vette

[ed_in_pa]

I have a 76 Vette L48 I purchased about a month ago with 51,000 original miles. I had it out yesterday for the first time a night. As I was driving the dashboard lights started to dim as well has the headlights. The meter on the dash appeared to be negative when I turned the lights on but when I stopped and turned the lights off it went to positive. It got so bad I had to pull over and turn the lights off to avoid stalling. As long as the lights were off it seemed to run fine. I don't know how old the alternator is but I do know the battery was replaced very recently. Does this sound like I need to replace the alternator and if so what AMP ?

 

[bill81vette]

yup sure does... your alt quit charging so your vette was using what ever it could for electricity aka the battery I dont know what amp rating to tell you but dont be suprised if you have to charge or jump the battery to get it started again...bill

 

[rgtrough]

Electrical problems

Hey Ed, the great thing about an alt. problem is that it is an easy check. If you have a shop in your area that rebuilds starters and alt. then you can pull it off the car and take it to them. If it needs rebuilt it is relatively inexpensive. I had mine done for $36.00. Some parts stores also can check them for you.

Make sure your alt. belt has the proper tension, that it is not slipping at rpms higher than an idle. This happened to me.

If the alt. checks out OK then the problem you are having could be a short in the headlight, dashlight, or running light areas. Not such an easy check.

Look for the obvious and easiest first. peace Bud :cool

 

[ed_in_pa]

Thanks for the info, I would probably replace the alternator if it is bad, if that is the case, what AMP should I go with? I know Ecklers has from 61 amp to 140 amp.

 

[ed_in_pa]

Just checked Pep Boys, they have a remanufactured 63 amp alternator for $44.99 with a 3 year warranty.

 

[Vettehead Mikey]

Thanks for the info, I would probably replace the alternator if it is bad, if that is the case, what AMP should I go with? I know Ecklers has from 61 amp to 140 amp.

If you have A/C car, you want the 61 amp. If it's non A/C, the correct one is 42 amp.

 

[ed_in_pa]

I think I'd like to go with a little more amps. Maybe between 70 - 85. Any suggestions where to get also chrome vs. original?

 

[curtis]

You don't need to take alt off to see if it is dead. Measure battery voltage with engine off. Then start car and measure again. If voltage is lower when running then alt is no good. If it is higher than it is good . May be a possibility battery has internal short. Auto Zone here can do load check in the car for free. Excellent chrome alternators from Jegs and Summitt. I just bought their chrome housings and put my old parts in it.