Brake switch malfunction causing TCC not to lock up.

[theairguy]

So To make a long story short, my M1165a brake lights stopped working while driving in town. My brakes are very touchy and barely have to be applied to stop.. so not much travel in the brake pedal. So if you reach down and push on the switch you have brake lights. I followed the instructions on how to adjust the switch, still not enough to turn on the lights. Tried adjusting the rod, not happening either. So I ordered an new switch off of flea-bay. When it got here I installed it and it had to move even further then the original to get the lights to come on. So I made my own linkage which works very well and you can adjust all you want. What I have ran into now is the adjustment is so far forward to actuate the brake lights that the Transmission is getting the signal the brakes are always applied. (code 37). So I put the old switch back on with my new adjustment rod, and it apparently has bad contacts inside because the lights either flicker or are real dim when the brakes applied. So I put the new one back on since I have been running around town, and never get above 40 mph. I have just ordered another brake switch from hummer parts guy, it was double the price of flea-bay.. lets hope this works... My rpms are way to high to take out on the open highway...

 

[Coug]

If you don't have LED bulbs or assemblies in the rear, you'll want to get them. The switch doesn't seem to like the load from incandescent bulbs, so they fail much faster if using them.

 

[frauhansen]

I had the same problem on my rig. Feld no 5mm pedal movement from nothing to emergancy brake.
Adjusting this both switches so the brake light AND the gearbox receives a clear signal, no way!

So i took a shortcut. I ignore the switch for the gearbox and "bound" the signal to the brake light by using a relais.
I don't remember whether the signal to the transmission is closed or open when the brake is activated. You may have to measure this briefly.
As soon as the brake light gets the 24V, the relay closes/opens and delivers the signal to the transmission.
The adjustment horror is done with it. Just set the brake signal, the rest is automatic.

 

[AnimalMother73]

My 1151 didnt even have the switch when I got it. I did the same and bought it on ebay. Then I got the connector arm from HPG. Installing both this wknd. Hope it’s not a bitch.