I've got an aftermarket booster master and proportioning valve and the proportioning valve has a hydrologic brake light switch installed but there are no installation instructions for the switch just a 2 wire harness.
My Jeep is an 88 so I have the old Ford brake light switch which has 3 wires on it.
I'm not sure how to wire this thing up and I'm hoping someone has some experience here!

 

did the research of the wiring diagrams that I could. Obviously one wire is power in...other wire turns on brake lights when pressed. at the same time it sends power to the cruise control computer..power to computer brakes on...no power -brake off. You need to verify what wires are connected on yours with brake. If they both are connected to the 3rd with brakes set then you can splice both of them to the output wire on your new switch.

 

Another diagram for an 88...another brake switch that goes to tranny lockup contrl...how many brake switches do you have under there..and what color are the wires in question. Might not have been a factory install that you have...

 

I'll have to verify the wire colors tomorrow but I know their is a 2 wire plug and a single wire plug and the single wire runs to another switch that keeps contact with the brake pedal.
Kind of like a door light switch in a door jam of a car it seems adjustable.
The instructions specify that if I don't adjust the brake plunger correctly this can cause the brake lights to stay on and I assume it's that one wire switch that causes this.
I really appreciate your help.

 

Okay so on the main plug (2 wire) one was red and one was black with a blue stripe. I connected them color accurate and the brake lights work great!
No idea what that 3rd wire was for I assume it was the cruise control but since it already doesn't work I'm not worried about it.
Thank you again for the help amigo!!