Intermittant or No Cruise Control Especially After Adjustable Pedal Fix

[vegasmarauder]

Yes, this switch out of adjustment will kill the cruise control.

By the way. Do not put the switch back in until AFTER you have connected the pedal rod to the master cylinder. Also do not push on the plunger manually. The plunger has a ratchet mechanism on it that cuases the plunger to retract in and will never come back out. The correct sequence is to install the entire thing and the pedal rod. The last thing is to slightly depress the brake pedal by hand and then install the deactivator switch. It just goes in the slots and turns about a 1/4 turn. If you try to do it without pressing the brake pedal slightly you may inadvertently move the plunger and the cruise won't work. In some cars even if the plunger moves one click in, it will open the switch. You can compensate for this by slightly bending the metal contact lever a little closer to the switch. Once you release the brake pedal it automatically sets the correct spacing for the plunger, that's the purpose for the ratcheting mechanism.

Sounds more confusing that it is reality.

[Coupe]

@vegasmarauder:
thank you for your DIY, it would be worth a mind!!!!

[vegasmarauder]

Thanks. I've learned a tremendous amount from others on here so want to do my part.

[Ken]

Thanks for bringing up this old post. Can definitely be my problem, pedal gear was changed in parking lot of the Homewood Suite in Atlanta at MV11. Cruise didn't work on way home or since. I will check into this. Never connected the two issues.

[vegasmarauder]

Another quick way to check (and avoid having to crawl up under the dash) is to probe the solid Orange wire at the cruise control connector. It should be the second wire from the front of the car. It should have 12V all the time, even with key off. It's powered from the same feed for the brake lights, so if you have brake lights, but no 12V at the orange wire, 99.999% of the time, it's the deactivator switch. Then have someone pull up firmly on the brake pedal and see if the 12V shows up at the orange wire.

[Chi Stallion]

Big thanks to the op for this thread helped me figure out why my cruise control wasn't working.

[BAD MERC]

I did the pedal repair and have read and read and reread this thread trying to figure out what the pictures are showing. At the moment I have a repaired pedal and no cruise. The brake lights work with what I assume is the brake light switch mounted on the master cylinder pushrod. I am guessing the plastic plunger is for the cruise but seems to be depressed when the pedal is released. So far I have taken it apart and put it back together four times and still no cruise. What is it we are fixing/pinching/bending?

[MERCURY 2003LSE]

I did the pedal repair and have read and read and reread this thread trying to figure out what the pictures are showing. At the moment I have a repaired pedal and no cruise. The brake lights work with what I assume is the brake light switch mounted on the master cylinder pushrod. I am guessing the plastic plunger is for the cruise but seems to be depressed when the pedal is released. So far I have taken it apart and put it back together four times and still no cruise. What is it we are fixing/pinching/bending?

Did you figue his problem out yet with the cruise control ?

[BAD MERC]

It appears the metal tang (could not comprehend what I was looking at) might be bent out a tad. The plunger switch makes contact with it and presumably that is how it operates but I have yet to test continuity based on switch operation. I might bend the tang back and put eyeballs on it to see it it's depressed all the way. This is my first pedal repair and I'd like to offer this to other members just as I do LCM repair, HVAC O rings, and now pedal repair. Sending somebody back across the state with no cruise would mortify me.

[vegasmarauder]

_Some clarification. The deactivator switch has to be removed before disconnecting the master cylinder push rod. This is because the deactivator switch has a ratchet plunger in it. Once the pedal comes all the way up it sets the correct switch clearance so there is continuity with pedal released and open circuit with pedal pushed. If the pedal is allowed to go back released from the push rod it will push the deactivator plunger further back resulting in an open circuit with a depressed pedal. If you make that mistake, you either buy a new deactivator switch that has the plunger at the beginning of its travel or you may be able to bend the metal lever on the pedal and get the switch back in the correct location. The switch plunger can not be released once it pushes in and ratchets.
Also make sure you push the brake pedal down when re-installing the deactivator switch. If not, you can inadvertently push the switch ratchet plunger further in and end up with an open circuit with released pedal

[mm svt]

Lots of questions answered from reading older posts, thank you.