Kamilo77

Haven't started my 81' in about a month, I have been working on the gauge cluster, steering bearing and putting a new wheel in. All that got done and I start the car and now the alternator isn't charging the battery ???

Previously, after starting the car the warning light would come on, I would have to rev to about 2500 rpms then the voltmeter would show the alternator charging. Now, nothing. Fuses check ok. Thoughts??

RFJ

Have you checked the output with a meter? you may have just muffed something up with your work. I would check with a meter and if it is not charging go back over your wiring and recheck it. Do you have a diagram of the wiring?

Kamilo77

Thank you for the reply everything seems to be working fine now, I swear this thing sometimes has a mind of its own.

jwillman

I seem to remember something about the light bulb having to be good to initiate the charging circuit. Older cars also have the resistor on the back of the alternator gauge between the two posts that is related to the charging circuit.

http://www.stuttgartperformanceengin...SHPROBLEM.html

GlenL

The light shows current flow through the exciter circuit. There's a resistor in parallel with the bulb as there may not be enough current through the light. It needs to be "primed" before it'll pump. Once the alternator starts working, it puts 12V on the exciter itself and, with 12v opposing 12v, no current flows through the bulb and it's "off."

A simple test is to turn the car on, but not running, and check for 12V on the little connection at the alternator. You'll need to work back, or forwards, to see where the fault is. Likely in the foil connectors or on the pod itself, based on your recent work. It runs through the 12-pin connector so easy to get at there.

Kamilo77

Wish I would have known when the cluster was off but...

1) The bulb for the Voltmeter that the alternator relies on is burned out.
2) After replacing the fuel sender and fixing the wiring to the harness my fuel gauge reads 3/4.

If the bulb is burned out is this the replacement?

http://shop.928intl.com/mobile/Bulb-...41%2D958%2D00/

Also do I need the resistor or should that be ok?

Kamilo77

Any input? Probably going to do this job soon.

Kamilo77

Just wanted to confirm I finally replaced the bulb and now the alternator circuit is as it should be and charges at idle. Thanks!