1995 F53 Cruise Control not working

[ArTravler]

My cruise control has stopped working. I believe it stopped working when I had an incident with a frozen LH front brake caliper. The break fluid boiled and my pedal was going all the way to the floor. I had to travel a bit before I could stop at a safe place. I was applying a lot of brake pressure to slow down and stop the RV!

Is it possible the safety switch in the master cylinder opened and did not close (BROKEN)? This is a normally closed switch with constant power. The switch opens when 5-10 Lbs of pressure are applied to the brakes.

I have a trouble shooting sheet for the cruise control amplifier but so far I have been unable to locate the unit. Does anyone know where it is located? I would assume the location is common on any 95 F53 chassis.

If I can not find the amplifier I believe I can validate or eliminate the pressure switch suspicion by disconnecting the plug and jumping the connections in the disconnect plug. If the switch is the problem the system should work.

Comments please!

[Jagtech]

Check for a damaged brake pedal disengage switch. Some types use a dedicated switch mounted at the brake pedal, others use the brake light switch to disengage. Its an easy check....

[Wanabee FTer]

Sometimes you can lift the brake pedal with your foot then press the cruise control button to get the brake switch to engage. If the cruise works you know what's wrong. Easy way to diagnose a miss-adjusted switch.

[jeepfreak]

Wasn't there a recall for those? Possible fire hazzard. Just a thought.

[subford]

No vacuum switch mounted on the brake pedal.
Yes there was a recall for putting a harness on the Speed Control brake pressure switch with a fuse in it.

The Speed Control Amp. location:


Brake Pressure Switch:

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[ArTravler]

Quote:

Yes there was a recall for putting a harness on the Speed Control brake pressure switch with a fuse in it.

Thanks for the photos. My F53 has the recall modification incorporated. If it has a fuse in place of the switch is the fuse a reset type fuse or does it just blow?

I see you still have the old switch. My old switch was mounted directly to the brake manifold. The Ford Dealer removed the old switch and installed the new part with a small pig tail connector that plugged into the old harness connector.

I thought the new part looked really small for a new switch. Now I know (a fuse instead of a switch).

[subford]

You retain the old pressure switch.
They only unplug the old switch and plug the new harness into the old switch and the harness that was plugged into the pressure switch before.
The fuse is inside the new harness.

The above ohoto was a before the Speed Control Mod and the one below is an after.


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[ArTravler]

Quote:

You retain the old pressure switch. They only unplug the old switch and plug the new harness into the old switch and the harness that was plugged into the pressure switch before. The fuse is inside the new harness.

The recall harness on my f53 is quite a bit different from yours. The switch mounted to the master cylinder is also a lot smaller.

I put a jumper on the brake switch harness plug this afternoon and low and behold that is what the problem was. Either the switch failed or the fuse blew.

I guess the Ford F53 chassis are different to. There are very few chassis parts inside the dog house on the Holiday Rambler. Most of the stuff are Holiday Rambler add ons.

THANKS FOR THE HELP!