Charging Light on Dash Not Coming On

[alsgro]

Hey, all.

Does anyone have an idea why the charging light on my dash isn't coming on with the key in the "on" position?

The oil pressure light works, but the battery light doesn't. I've taken out the bulb, swapped it into the oil light position, and it worked, so I know the bulb is good... Oh, how I wish it was just the bulb!

I've had a poke around, and it doesn't look like anything has come loose on the alternator or starter. I'm reading only 12.8 volts at the battery with the engine running, so I'm pretty sure the charging system isn't doing squat currently. Could it be a bad regulator?

Mine is an '81, if that helps.

[spider2081]

your charging light circuit must work in order for your alternator to work. An easy test is to remove the violet/black wire from the alternator and connect it to ground. Then turn the ignition switch to the on position and the light should light up. If it does the issue is the alternator if it doesn't the problem is in the light circuit.
If the problem is in the alternator and it is the original Bosch alternator your problem could be the voltage regulator/brush assembly mounted to the back of the alternator with 2 screws. This can be changed without removing the alternator. I would disconnect the battery neg. terminal first as the power to the alternator output post is hot all the time.

[alsgro]

Thanks so much! I'll give this a try today and report back.

Best!

[alsgro]

Thanks for the tip Spider2081! The dash light does come on when I put the violet wire to ground, so I guess the next step would be to try to find another regulator? Any thoughts?

[spider2081]

I prefer to purchase my parts from the vendors that support our cars. Here is a link to a generic voltage regulator you could try sold on Amazon.
https://www.amazon.com/gp/product/B005L ... UTF8&psc=1.

They are a little tricky to change while the alternator is on the car but certainly can be done. As I mentioned be sure to disconnect battery before trying to remove the regulator. I feel the odds are better than 50% the regulator will cure your problem. Of course having the alternator rebuilt is a better long term solution.

[alsgro]

I found one at O'Reilly, so I'm gonna give that a try. I'll let u know if that does the trick. If not, I'll probably get the 95A upgrade.

Thanks again for the help!

[alsgro]

Hey, all! I forgot to report back that the voltage regulator did the trick! I didn't have any trouble getting it in on my '81. I just took off the belt and slid the alternator around to get access. Not bad, really.

Thanks again, all

[spider2081]

Great!! Enjoy your ride.