There's the problem. The TCC switch, on the brake pedal support, is telling the cruise control that you have the brakes applied, which shuts off the cruise, (or in your case, prevents it from engaging). This will also prevent the transmission from shifting into overdrive. The switch only has power when the key is in the RUN position, and it does not control the brake lights, (that's why the battery doesn't go dead over night).

In the instrument panel fuse block: ABS fuse #22 10amp runs to the TCC switch through a brown wire. It has battery voltage in the RUN position only. The brown with white stripe wire runs from the TCC switch out to the cruise module pin "D".

Either the switch is shorted internally, or it's out of adjustment. Bottom line is if the brown white stripe wire has voltage at the cruise module, the cruise will not work.

 

Gotcha , I'm gonna put my eyes on this switch (on the brake support)? You know my overhead mpg gauge went from consistant 17.6 to 14.5.......maybe cause it wasnt shifting into overdrive? I'll check back
THANKS

 

I removed switch & it's working opposite. Not pressed- light is on/voltage, press switch- light goes off/no voltage. So does this tell me the switch is bad ?

 

Woops, nope, sorry, read the schematic wrong. Brown white stripe wire must have voltage with key on and brake pedal released. No voltage when the brake is applied.

Back to the blue wire. Does it show voltage with the set button pushed?

 

Yes Blue wire shows voltage when SET button is pushed.

 

Just double checked the schematic....

At the cruise module:

The brown with white stripe wire should show battery voltage with the brake released, and the ignition in the RUN position. Must show zero volts with brake pedal applied.

Brown wire must show battery voltage with the ignition in the RUN position.

Grey wire must show battery voltage with the cruise switch ON and the ignition in the RUN position.

Dark blue wire must show battery voltage with the cruise switch ON, the ignition in the RUN position, and the SET button pressed.

Black with white stripe wire must show less than 5 ohms resistance to ground at all times.

 

Everything is yes until grey wire.
Grey wire has no voltage at module..........and my ohm meter must be screwed up. It just reads a big L when I check ohm's.

 

Grey wire turns on the module. See if the grey wire shows battery voltage at the switch when you turn it ON, with ignition ON.

EDIT: If the grey wires does not show voltage, the multifunction switch is faulty. Depending on what the problem is inside the switch, there might be a "work around".

 

so find the grey wire coming off the blinker switch on the steering column ?

 

Yup, should be a plug on the driver side of the column with a bunch of wires in it.