First the question. How does the brake light switch work? Is it a normally open switch when compressed and closes the circuit when the switch is extended? My brake lights have decided to come on all the time now and I'm hoping that it's simply the switch hass gone faulty. Just not obvious which one the switch is as I have cruise control and I know that there is a release circuit on the brake.

Now for the customary rant. If it isn't one thing, it's another. I struggled through a very hard rocker arm change and adjustment. In one of the four removal and replacements of the cover, I shorted out the choke warmer fuse. No big deal; 20 AMP fuse on the top, right side of the box according to the service manual. What the service manual doesn't say is that besides the horible placement of the fuse box in these things, there is so much wiring, cables and junk in front of the fuse box that you can't even see most of them. You shouldn't have to change a fuse using the Braile method. Only took an hour. And naturally, something else (the brake switch) had to break while I was there.

 

It is a very simple switch to replace. $5.49 and NAPA had it in stock, go figure! I had been working on mine a couple weeks over at my friends house. When I finally drove it home, my wife followed me and called me on the cell to tell me they were not working. When I got home, I messed with it a little and determined that was the problem. Took less than 5 minutes to replace.
Just hope that's the problem. Good Luck!

 

I think it was the problem. I bought a new switch at a local parts store ($12, but it is CA ). Took off the old one and they don't match, but at least the brake lights are off now. Had to go to GM and order one for $16.

You're right too, not hard at all though it's never easy doing anything under there.

 

There are two switches. One for cars with Cruise Control and one without.

I think the part I enjoyed the most about changing mine was standing on my head.

 

Kind of makes you wonder how they assembled these in the first place. Without the seats and the dash, I still think it would be awkward in there.

 

Mine started to do that too. My mechanic slid in there & bent the bracket holding the switch, works fine now! He said he's seen them bend a little before.

 

The switch for brake lights is a normally closed switch, but is compressed (open) in the normal brake un-applied position. If you had an 82 or a car with overdrive, there is a separate portion of the switch that is normally open, but is closed in the un-applied, driving position.