Help! Self lighting brake lights on '94 Burb

[Big T]

Ever since we bought the '94 Burb the brake lights will mysteriously flash by themselves with vehicle parked, no key in the ignition, no one in the vehicle. Seen this numerous times. Even neighbors have come up to point it out. What could be causing this? Where do we start? It does have an aftermarket brake controller on it.

 

[THEFERMANATOR]

Shorted out brake controller, bad brake light switch, or a broken brake pedal return spring would be my guess. I just looked and it shows the 94 as using the switch that hooks onto the pedal pivot, and many of those styles used a pedal return spring on them to prevent the pedals weight from activating the brake light switch. I would hook a bungee cord onto it to hold it up and see if it does it then. If it stops then I would add a return spring to the pedal, if it doesn't put a new switch in it.

 

[Will L.]

Factory alarm problem possibly.

 

[SmithvilleD]

I just replaced my brake light switch @ 195k miles. Solved the problem. Was causing just the type of thing you mention. Co-workers would tell me my brake lights were on, but didn't see it myself to confirm for a couple months. Finally when probing the switch wires to see if it was the problem, the switch failed to the point it wouldn't even light the tail lights.

The switch retaining clip can be a bit of a pain to get off. Get enough light up in there to see what you're doing & understand how the clip works. It wasn't easy & got a few scrapes, but from reports I'd read, I was sorta expecting worse. Once I understood how the clip worked & got enough light to see what I was doing, I worked it off with a long, narrow screwdriver.

O'Reilly Autoparts didn't stock the little kit of retaining clips they offer, but they ordered it & came in a couple days. I didn't wind up bending mine up removing it, but I've read several times it's a good idea to have a replacement on-hand before you start the switch R&R so getting a replacement clip doesn't keep you from quickly finishing the job.

 

[Big T]

My son said that he clipped the wires at the brake controller that came with the truck and so far he hasn't had any flashing lights. He has a Prodigy 2 brake controller from the '95 wreck that he plans to eventually install.