Cruise doesn`t engage. Pick-a-part has a few XJ`s proper year for parts.
What parts should I try first ? Brake switch , CC module (where is it) ?
For a small extra fee they have a "warranty" so if part doesn`t fix it , I`ll just try something else.
Anyone have experience getting theirs to work ? What fixed it ?
I`m willing to try and find the part it needs because everything else works great.

 

The brake light switch IS important as it will disengage or prevent the cc from engaging in the first place. You could try lifting up on the brake pedal and try to engage the cc. If no change, then i'd suggest checking the vacuum to the cc. Little thin plastic line coming from front passenger side tees off, one line to the cc servo and one thru the firewall to your heater controls. Even a slight vacuum leak could affect cruise. From what I've read, the servo itself is the problem 99% of the time. I replaced mine with a salvage part for about $27. You might need to swap the cables, but it's a pretty easy fix. The servo is hard to miss.. it's right next to the wiper reservoir. It has a cable to the throttle, the vacuum line, and the elec. connector. Good luck

 

Wow...saw that servo in your picture and thought maybe I should get it.
Wonder if other years would work besides exactly 1990 model.