Exciter Wire Voltage

[91Bird305]

I'm trying to track down an issue with my alternator.

I checked the voltage on the alternator while it's running and it's 11.88 volts roughly. So something is obviously not running right. When I check the exciter wire on the alternator while it's running, I am only seeing around 2 volts. Is that correct? What should the voltage be on the exciter wire?

I also took the alternator in to have it tested and they said it passed. So I'm running out of options here.

Thanks.

 

[David65]

Not sure what that wire would be under normal running conditions. The exciter wire you refer to is actually called the lamp lead, because it connects to the dash lamp. The stock wiring diagram is here: http://www.turbobuick.com/forums/2425762-post2.html Lamp lead (L terminal on the regulator plug) through the dash lamp and a fuse to +12V that comes from the ignition switch. Pretty simple circuit. How is your setup wired? Did it have a working dash lamp before? Did/does it light with the ignition key on but the engine not running? In a pinch, you could connect a resistor from the L terminal to a switched +12V source like is shown in the schematic. The resistor would take the place of the Volts Indicator on the dash.