Brake Light Question

[gkurts]

Hi - I have a 2005 GMC Z71 and have had a nagging issue with the brake lights / brake pedal for a while... The brake lights come on as they should when you press the pedal, but as soon as you start to release pressure the lights cut off - not when the pedal is fully released, but as soon as you lighten pressure on it. Any ideas on what I should check? I appreciate any input!

[asilverblazer]

I thought this was unique to the GMT-900, I'd suggest a new brake light switch.

[MS3DALE]

My '99 and '04 both did the same thing

[hubbycap]

I thought this was unique to the GMT-900, I'd suggest a new brake light switch.

 

+1

 

Cleared the problem up on mine.

[gkurts]

Well, no luck. I managed to get it figured out, though.. Inside of brake switch is a spring that controls the position of 3 sets of contacts (2 NC, 1 NO - I'm assuming the NO set is for the brake lights). The spring had too much pressure on it causing the NO set to open back up too soon, so shortening the spring (seems to have) fixed it. Instructions follow for anyone interested.

 

1. Get a new brake light switch in-case you break something.

 

2. Remove the brake light switch. Unplug the harness from it, remove the retaining clip, slide the assembly left, and voila! Install in reverse order *note that the booster rod goes between the open slot on the switch assembly*.

 

3. Open up the switch assembly - there are 5 clips that you have to push and the cover comes off.

 

 

4. Remove the spring (hold your hand over it or you get to watch it fly across the room).

 

5. Using lineman's pliers, cut a *very* short piece off of the spring (did I recommend eye protection?). You can always cut a little more off later if you don't get enough this time - I actually made 2 cuts.

(I cut this much, plus about 1/2 twist from mine)

 

6. Put the spring back in and make sure the contacts worked as before.

 

7. Reinstall switch assembly and test. Repeat as necessary.

 

Hope this helps someone in the future.

[huero626]

My V-Max also does this, the brake lights also don't turn on if the truck isn't on.

[hubbycap]

Great Greg, good DIY instructions. My problem was under waranty but I would have spent a heck of a lot less time doing this field mod than getting the warranty work done.

[Darkanion]

Interesting. I may have to give that a try on mine. I know it's under warranty. But, I've seen several posts where people took theirs in and it still wasn't right, when they got it back. Thanks for the how-to!

[y2kz71]

Is this switch the same on the 2008's?

 

I wanna do this today

[jdubub]

once you pull the screw out on the gmt900s how do you get that clip off in order to pull out that bolt?