rockstarslevin

when i get in my car to start it all my idiots lights come on as usual. im assuming as a test to make sure thier working, only some times they dont go off. the car runs normal and nothing electrical acts up just all those lights stay on and its kinda buggin me. it doesn't do it all the time just every now and then. has anyone had this problem???? btw its a 91 vert

Turbo II Rotor

iTrader: (2)

Your alternator is bad.

rockstarslevin

my alternator is good!!

cerm78

I have trouble with my idiot lights too, some of them are not working, even when the bulbs are good.

As far as I have researched, all lights should come on when the ignition is on and the engine is not running. The running condition is detected using the alternator. When the alternator is generating, the W/B cable on the idiot light plug will close a ground circuit and current will flow from the B/Y cable to the W/B cable. If that circuit stays closed during normal operation, there must be some negative logic circuit somewhere that had gone bad.

I don't know if the voltage inversion (voltage to ground) logic is done on the alternator or the idiot lights themselves, I haven't tested that. What I know is that W/B is the cable that sets the signal to turn on all lights.