Brake switch wires

[idrivejunk]

This is a very common GM brake / cruise / TCC switch design from the era surrounding the turn of the century. Can anyone tell me which two wires in the four pin connector are cruise and which two are torque converter? Lamps are in the two pin one.

TIA

[idrivejunk]

Alright then. Any suggestions for a course of action which might enable me to form a theory about which wires are cruise and which are TCC?

It seems I have generated another unanswerable question and will not get cruise back. No big deal but I used it a lot to stay out of trouble.

[kb426]

I found this. I don't know if it's correct.
The switch has six wires, two for TCC, two for brake lighting, and two for the shifter interlock.

The following is the brake switch connector pin positions, wire colors, and functions.
A: White - Out to brake lights
B: Orange - Always Hot power in from Stop/Haz fuse 1 in cab fuse panel
C: Purple - Out to PCM/Cruise/ABS brake signal input
D: Brown - Hot in Run power from Brake fuse 18 in cab fuse panel
E: Light Green - from Park/Neutral switch on transmission
F: Dark Green/White - to shifter interlock solenoid

[idrivejunk]

Thanks. 

I wondered about shift interlock but when that was unaffected by anything I tried, I changed my assumption.

As soon as I can get under the dash again, I will see whether your wire colors jive with whats there. Staying home from work today due to back damage done doing that very thing too soon after hurting it lifting pickup body panels. Visual access to brake switch requires hooking heels over headrest.

Again, thanks.

[idrivejunk]

Well, nope. Swing and a miss. I got my phone down there.

Looks to me like the top switch is red and brown.

The big switch with the blue connector unplugged has a two wire plug, orange and tan (?).

Then the four wire plug is:

red, dual dk grn / wht, orange (or pink?) and purple.

Been driving it a couple days with the blue plug unplugged as shown. When and if I get up around 50, well I'm  not sure what might be going on. Could be some trans issue, could be me getting used to no lockup. The 3-4 shift seems like a bigger spread without it. After it shifts to fourth I tend to let off the gas anticipating lockup which normally hurls it a few mph faster. Additional throttle required to hold speed.

So I am hyper-wary and trying to mentally prepare for whatever. It manages a slight exhaust note now at least. If quiet and glass is open. No dip in MPG yet and WOT is good. But up to 50ish is all I know about. Seems good thus far.

[idrivejunk]

Removed purple wire from blue connector and plugged it back in. No change, no lockup, no cruise. End of story.

[idrivejunk]

Bonus!

I run with a hub unplugged to defeat ABS and TCS (traction control) and had tape over the TCS indicator and cardboard over the ABS one, which is real bright.

After my experimentation and disconnecting one wire, now the ABS light is not on. But traction control "off" indicator is lit.

I have no explanation of how this is even possible. But I'll take it.

For the record, without lockup MPG has not changed by so much as a tenth of a mile in two tanks of gas. But I constantly miss cruise control, it was an important weapon in my fight to retain freedom.