My '99 Suburban has not had brake lights for the last month or so. The tail lights, turn signals and flashers work. Third brake light doesn't work. My initial thought was the brake light switch behind the pedal but, on using the brake pedal, the cruise control suspends every time, so that has pointed me in a different direction. I've searched for ideas and came up with a faulty multi-function switch as the answer, so I ordered a new one. It came in yesterday and I spent 2 hours swapping it, but still no fix. At this point, short of replacing individual wires, I'm stumped as to what the fix should be.

Wondering if anyone has additional ideas to keep me from pulling my hair out? I don't want to throw more money at it without knowing that it will fix the problem, but I need this vehicle to transport my kids around. Does anyone know for certain if the brake light switch is (or is not) the trigger for suspending the cruise control?

All thoughts on this subject are welcome and will be entertained! Thanks for your help.

 

The brake light switch does suspend the cruise control. The switch however has 2 circuits, one for the brake lights and the other for the cruise control.

 

As I was typing up my last question, I came to the realization that my testing of the brake switch was a bit incomplete. So I got down on my back under the dash (the worst part of working on a car, if you ask me) and got the electrical connector off the brake light switch. When tested with a multi-meter, the power (orange) wire had 12 volts. Then I used a jumper from the power wire to the brake light feed (white) wire. Low and behold, I had lights!

The brake light switch has two circuits in it: one for the brake lights; one for the cruise control (thanks oldchevy!). The switch for the lights was bad. an hour later I had the new one installed and working like a charm! Problem solved, and with a lifetime warranty!

Also, by replacing the multi-function switch, I fixed a problem I had with the intermittent settings on the windshield wipers, so I'm happy to have changed that as well.

Thanks for the help.