Testing the Cruise Brake Switch?

Sam Woodson

Registered User
After I put the dash back in, I noticed the cruise still works, Resume, Accel, Coast, etc. However, when I hit the brakes the cruise does not dis-engage. I checked the wire connector (harness with 2 wires, shaped kind of like an L) it was on as tight as it would go and does not seem possible that I could have reversed it.

How do I test that switch? Before buying a new one I want to be sure that is the problem.

Anything else to look for? Everything else in the car is working as far as I know.

Thanks,
Sam
 
You need a digital multimeter. Use the ohm or continuity tester to see if the switch on the pedal makes and breaks when you push on the pedal.
 
Sam Woodson said:
............. when I hit the brakes the cruise does not dis-engage. ............How do I test that switch? ...........
The switch is used by the brake lights and the cruise control. The switch closes when the brake pedal is depressed causing the brake lights to turn on and the cruise control to disengage. The switch opens when the brake pedal is released causing the brake lights to turn off and allowing the cruise control to be activated.
A quick way to test the switch and the wires that run to it is to check for on/off operation of the brake lights when pressing and releasing the brake pedal. In addition, check that the brake lights come on as soon as you begin to depress the pedal.
Did you remove the brake switch when working on the dash? If so, the plastic bushing could have fallen off. This may cause the brake lights to come on only after the pedal has travelled some distance and the cruise control to disengage only when the brakes are slammed on.
 
Sam,

What year is your car? The earlier ones have a vacuum-operated cruise override. There's a little vacuum valve that is opened mechanically when you step on the brake. That can be adjusted (or misadjusted) easily. (This was the reason my cruise never worked until recently.)
 
It's a 90 model. I just found out tonight that the brake lights are NOT working! It seems no matter how hard I hit the brake pedal.

Now I am in Hardeville, SC (about 9 hours away from home) with No brake lights, no tools, etc.

I did not remove the brake switch, just the wiring connector.
 
The one time I lost my brake lights it was the the switch. Try unplugging and reseating the plug onto the switch and checking it's mounting and activation on the pedal. The switch may have just gone bad.
 
Looks like the switch. I took the Z shaped wire harness off the brake pedal, and put a paper clip in there, the brake lights come on. I'm calling around to local Ford dealers now looking for a switch.

Maybe they were working then after I put the dash back together and it quit working since, which would make me feel a little better anyway. I still can't believe no one told me. Anytime I see someone with a brake light out, I try to tell them at the next stop light, etc. Not to mention yesterday morning, I had to have a truck follow me onto base to a building for a pickup, he said "sharp car" but it would have been better if he said "No brake lights!"

Thanks,
Sam
 
Christmas eve day I was driving to my daughters and had a rear tire going flat for about 10 miles on the interstate. Not one person signaled me that there was a problem so I can believe that no one let you know.
 
You know, when I had my last Tbird SC, I had a flat, used Fix A flat, which didn't work. I had to drive home like 6.5 hours. I kept pulling over and adding air. It was the Dr rear, even when it was flat the car still drove great! It was years ago now, like in 96 but I think I made it all the way home, or possibly gave up and put the spare on, but that's not too great for the highway and a long trip either. It was a weekend holiday and I couldn't find any place to fix it.
 
Darn that switch!

J.D. said:
The switch is used by the brake lights and the cruise control. The switch closes when the brake pedal is depressed causing the brake lights to turn on and the cruise control to disengage. The switch opens when the brake pedal is released causing the brake lights to turn off and allowing the cruise control to be activated.
A quick way to test the switch and the wires that run to it is to check for on/off operation of the brake lights when pressing and releasing the brake pedal. In addition, check that the brake lights come on as soon as you begin to depress the pedal.
Did you remove the brake switch when working on the dash? If so, the plastic bushing could have fallen off. This may cause the brake lights to come on only after the pedal has travelled some distance and the cruise control to disengage only when the brakes are slammed on.

Hey JD,

Do you have a Picture/Breakdown of how exactly the bushings and switch assembly and retaining pin are put back on the pedal stud?
I spent ANOTHER half hour tonight trying different combinations of bushings and switch to get the tails to operate with a tap as opposed to the way it is now, pushing HARD on the pedal to get them to lite.... With no success...:mad:
Thanks!

Paul
 
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