I am troubleshooting a non-functioning cruise control on a 1994 Ford Ranger XLT 4.0. It is the older vacuum based system. I keep finding a cruise control relay listed among the parts websites. The relay is not in the fuse box or junction panel under the hood. Does anyone know it's location (assuming it uses one). Thanks!

 

All cruise controls used Vacuum to hold throttle open, until "drive by wire"(no throttle cables) came around

No relay involved, diagrams below

What are the symptoms?

 

Stopped working. Checked fuse (it was good) verified voltage in and out of fuse, verified throttle cable attached to servo is functional. Replaced the vacuum supply line into the servo as it was 25 years old and squishy, changed control buttons on steering wheel. Verified brake lamp switch works. Nothing helped. So at this point given how basic the system is, must be the servo or the speed control amplifier located behind my glove box.

 

And the horn works so you know the system is grounded?

I assume speedometer works, so the cable and gear is OK, make sure the VSS on the cable hook up is plugged in, and unplug it and look at the wire contacts to make sure they are clean

Does a light come on then you turn cruise on?

And manual or automatic trans?

 

The horn and speedometer works, It's an automatic. And on my model a light doesn't come on when cruise is enabled.

 

It's more than likely the cruise module up under and to the right of the glove box. Had two of them go bad on my Ranger... Nothing works when that unit goes bad.

 

Turns out it was the LED brake bulbs I installed. They were drawing too little resistance and the system disables as a safety precaution if it thinks you have no brake lights. I put resistors inline with the bulbs and now have cruise again.

 

Good info, thanks