My cruise control was only working when it wanted to, now it does not work at all. There have been times when I could turn it on and off many times then it would work. Now there is nothing the red light comes on in the button and thats it. Any ideas

 

Check all your vacuum lines for leaks. A lot of people including myself use Liquid Tape or similar to coat all the vacuum line connections and prevent leaks. D1 cruise control is known to have lots of problems and usually caused by vacuum leaks. If your problem is not caused by a vacuum leak then it is more than likely the ECU for the cruise control. Search the forum for the test procedure to verify where in the system your problem is.

 

Check all of your vacuum lines. There is one going from the brake pedal, through the firewall, intoa tee fitting. From there, one goes to the throttle actuator, and one goes to the front. Your vacuum pump for the cruise is under your jack. Take it out, and you will have to release 4 rubber nubs that press down into the wheel well. If you get under the truck, you can see the bottom of them.

 

Do you guys have a diagram of what this vacuum pump looks like? Thanks.