What are each wire color for the headlight wire harness? Trying to wire new DRL's

My headlights do not work. My high beams are fine. But I cannot find the relay switch anywhere

It was the dimming switch in the steering column with the cruise control on/off switch. Better off trying to find one used, because a new one from GM is $500!

Sometimes at night while driving my headlights will dim out for a second and while doing this I can hear a buzzing noise like something kicking on and off under the hood. Why does my car do this, the dash lights also dim as well when this happens. Please HELP!

I have checked all fuses and relays, all are fine. When I pull headlight switch the lights will not come on. But MFS will put on brights, daytime running lights work. All blinkers etc work. I checked for power at headlight connector. No 12 volts. Both headlights are out. But I can apply 12 volt to bulb and they work? Wipers act funny, and security light acts funny. Is this the BCM? What can I do? I am stuck.

Okay, I can load test it myself. So the MFS can stop the regular lights from coming on? I do know there is no click on the MFS. I have to hold back for high beams to stay on.

Thanks I will clean battery terminals. And load test it. Dave H

Okay, thanks so much. I will try all. Great to hear new information.
Dave

One question, check the voltage at the MFS or BCM? I believe you meant MFS.

Six cylinder two wheel drive automatic 125,000 miles.

I have one bright and one dim headlight. I have checked the ground which is for both headlights and they have the same resistance at the connectors the lamps seem fine. What is next?

Both high and low beam, the car has ambient headlight sensor.

Thanks.

Ok I've done lots of testing. Coming from harness to lights, there is power on every color wire except the light blue and black. There are 2 dk/ blue 1 pink 1yellow, 1orange 1light blue and black. So what does this mean?

I went under the dash to look for a ground on the left side of the brake pedal but cannot find any. Here is some extra information: At the headlamp on the right side I have twelve volts at connector pin F and H which are battery positive voltage, on the left at pin H the battery positive voltage. I have nothing but lights still come on dim instead of not at all. This car does DRL pin F on the left connector, if this helps
both grounds read no voltage connector to body bolt ground.
Bill

Found a ground that has two wires attached to one terminal near the brake pedal bracket, but after cleaning and tighten no change.