I am building a side project using an '02 Firebird headlamp control module, headlamp actuators (motors), and a switch. I have wired the module correctly with battery inputs for right and left motors, ground, park lamp signal, and headlamp signal. The motors run when the module is plugged in, but do not respond to headlight switch inputs. I understand that the module is a current sensing unit that turns off the motors when they encounter a load. I also understand that the module "closes" the headlamp doors when it recieves power so that it "knows" they are closed for its reversing logic to operate correctly.

At this point, when switched to park, nuthing should happen. When switched to ON, the module should command the doors to open until they hit a stop. They should then stay up until turned to OFF. The motors should then reverse, lowering the headlamps until it hits the lower stop. My motors will not do this. I bought a new module to no avail.

When the park lamps or headlamp circuit is OFF, do they switch to ground some way? My current setup only provides 12V when the switch is on. Am I missing a fundamental in this circuit? Thanks in advance. Frank

 

An '02 headlamp control module may be significantly different than those found on a ThirdGen. It may even connect through the body control module on the '02.

 

Thanks Vader. According to the part number, the module is the same as the late 3rd gens and fourth gens. On this particular vehicle, the headlight and parking light feeds branch (in parallel) off to the fog light relay and to the DRL module. The DRL and Headlamp Control Module are both solid state, so it isn't entirely clear what goes on in the "box." The headlight switch puts out the correct outputs when switched. 0 volts at OFF, 12V at the park lamp feed in the PARK position, and 12V at the park and headlight feed in the HEAD position. The module is getting all of the correct signals and is wired correctly. I'm not sure if the module is very sensitive to voltage drops due to headlight loads and such.

 

I have no experience with the later headlight door modules. If it is in fact a current sensing unit, you'll need to have some load connected to satisfy the logic.