Can someone tell me what makes the GEN indicator lamp to illuminate for the short time when the key is turned on and turns off after the start up? Would like to mimic this illumination to my top of dash FASTEN SEAT BELT pod. I don't have the seat belt warning wires attached anymore but thought this could be a unique way to illuminate it briefly on start up. Any help would be greatly appreciated.

 

All of your idiot lights have a lamp test function at startup. This is normal.

In the case of the GEN light, the bulb gets +12V on one side of the filament from switched power from the ignition key. The other side of the bulb is connected to the FIELD terminal on the voltage regulator. The FIELD terminal is connected internally such that if the alternator is not turning or not putting out any voltage, the terminal is connected to ground. If the alternator is putting out voltage, the FIELD terminal outputs this voltage. If the alternator is putting out the full 13.8V, you have the same voltage on both sides of the bulb, and the bulb goes out. If the alternator puts out less than that, the bulb has battery voltage on one side and this lower voltage on the other side, causing it to glow dimly. If the FIELD terminal is grounded, you have battery voltage on one side and ground on the other and the bulb is fully lit.

 

Thanks Joe,

So if I understand you correctly I should be able to pig tail off one side of the filament to illuminate the other bulb?

 

It entirely depends on how the seat belt bulb is powered.

 

Joe, what I tried so far was one side of the seat belt lamp I tied into the lead off of the Rallye Pack harness wire that is for the Alternator. The other side I grounded within the lamp harness for the dash. So the results are it doesn't illuminate until the car is running and stays on just the opposite of what I wanted. So its sounds like I could keep the wire tied to the harness but would need to find 12V to the other lead instead of being the ground?