How do you troubleshoot cruise control that suddenly quit working in 1998 jeep grand Cherokee?

Answer 1

Until an expert comes along to give a complete answer, I will provide some info to get you started.

The first step should always be to check to verify that the fuse(s) serving that device is not "blown," and is properly installed.

Always remember that a blown fuse strongly suggests that a short circuit has occured, and the fuse blew to protect the wiring from overheating which could result in a fire! So, when you encounter a blown fuse, always find and correct the fault which caused it, BEFORE REPLACING that blown fuse.

If your problem is internal to the cruise control, or inside a "computer," you will require the service of a professional automotive technician.

But to get started, the troubleshooting process should focus on:

1) a loose or "bad"[corrosion, etc.] wiring connection, or

2)an open circuit [a wire cut, pulled apart, etc.], or

3)a short circuit [a bare section of wire in contact with ground, such as bare metal,or pinched or chafed against a sharp metal edge, etc.].

For a more in depth discussion of electrial troubleshooting, and the use of tools/equipment, see the answer to: "How do I troubleshoot brake lights?"