Cruise Control

[Flyinhy]

Hi guys,

 I've been doing some traveling overseas for a while but I've been reading some posts from time to time. I remember reading someone's post about cruise control problems  and 2 pressure switches on the firewall in the Jenny compartment. The post stated that one switch is N/C and the other is N/O..... that should be why my cruise dosent work because they both test N/O. 

[CLIFF918]

Do your brake lights light when stepping on the brake?

[Flyinhy]

Yes, my brake lights work fine. 

[CLIFF918]

Ok then, one of the switches light the brake lights the other one cancels the cruse control. I just went through this as my cruse would not cancel when brake was applied. In my case the previous owner had a brake controller installed and hooked it up to the cruse cancel wire (labeled brake). Easy mistake.

In my 2002 Diplomat the two switches are behind a plastic cover above and to the right of the generator. You can remove the plastic cover if not sealed with too much goop. In my case it has about two times as much black foam as needed so I cut a door in the plastic cover to access the switches for testing. Sealed it back up with gorella tape.

there is a connector for each switch behind the box so you can disconnect and test the switch.

[Flyinhy]

Both of my pressure switches are exposed on the firewall. 01 Executive. 

I believe it was your posts that I read. Was one normally open and the other closed? I will do some more tests and study up on the schematics  when I get home from work. Thanks for the info. 

[David Pratt]

OK, so your brake lights work when you depress the brake pedal is depressed means the brake light pressure switch is functioning correctly. The brake light switch will be N/O in the rested state and will be closed when the brake pedal is depressed.

The other pressure switch is your cruise control disconnect switch and should be N/C when in the rested state and will go to open when you depress the brake pedal.

Just use a VOM to check either switch to determine which switch has failed. If both switches pass and are functioning normally then you have another issue. Another check to do is to starter the engine and turn the cruise control on and hit set to raise the idle. The engine will idle up if the cancel pressure switch is good.