Pontiac Repair: 97 grand am auto headlights, auto headlights, auto lamps

Question
my auto headlights aren't working.  do you think it is a relay or the sensor?  how to replace? thanks in advance

Answer
Hi David:

well there are 3 main components to this system the sensor in the dash, The insterment cluster and the control relay. I assume the headlight work when you manually turn them on both hi and lo beams? if so you know all the bulbs and wiring to them are okay. Without the aid of a scan tool It's going to be hard to find the issue here. the insterment cluster is the brain in the system. It converts the siganl sent by the light sensor in the dash and decides if it's dark enoughto control the auto lamps on. Ther is no way to tell if that part of the circuit is working or not without a sacn tool. the instermnt cluster then turns on the auto head lamp relay.. The most likly cause would be either a wiring issue at the auto lamp relay under the hood behind the bumper bar or the cluster is not turning on the relay. Very rarely to the sensors go bad. Good luck :)