I have a 1999 Pontiac Bonneville. When I drive it during the day the Daytime Running Lights come on and run fine. Then when it gets dark outside the lights go off automatically.

The problem is that the Headlights do not come on as normal.

I can get by this by manually turning the lights on but I like the convenience of not having to turn the lights on and off.

Since the Headlights work I assume that this is not a fuse but do not know what parts make up the Twilight Sentinel. I am assuming that there is a sensor that detects daylight. I also assume that this is what turns off the Daytime Running LIghts. If this is the case this is working. The **** on the lights for the Twilight Sentinel seems to be tight and turning fine.

I am not sure what else to check or could be causing this. Any help I could get would be appreciated.

i could be wrong, btu i believe there is a separate power feed to the headlamps from the manual switch and the automatic... maybe someone else can chime in on this

Sentinal was a crap shoot....I've had nothing but problems with mine as people on the board.....I think it'* the switch itself that goes bad.

Do you have your car light set to flash when you lock and unlock with your fob? And notice it doesn't flash? If it doesn't like mine.. more then likely it'* the Lamp Control Module.. but I haven't located one at decent price yet, so not 100% cause I never verified it..

I'm use to it now.. good part is during dusk dawn.. I can have just the Foglights on without ever using my headlight kill switch