I’ve been trying to add cruise control to my 89 MJ 4.0 5-speed with parts pulled from junkyard XJ’s. I believe I have everything and have tried a bit of troubleshooting but can’t get it to work. Any help or insight would be much appreciated.
Here’s the install list:
• cruise control wire harness
• cc harness plugged to “ACC” in fuse box on truck with inline 4 amp fuse unbroken
• speedo cable switched to two piece with speed sensor
• speed sensor plugged to cc harness
• brake switch swapped out for the one with extra terminals - plugged to cc harness
• brake sensor (aka vacuum dump valve) & bracket mounted and properly adjusted on brake pedal with the sensor plugged into connector from stock wiring harness and big vac line going to servo
• servo mounted with cable connected to throttle body and connected to both cc harness plug and stock wiring harness plug
• yellow cc module plugged into cc harness
• cruise equipped turn signal lever installed and plugged into cc harness
• football-shaped vacuum reservoir in place of the ball one with small vac line running to servo
Here’s all I’ve done in terms of troubleshooting:
• I have multiples of the module, speed sensor, servo, and harness and have tried various combinations excluding the harness because I know it needs a repair.
• I have checked the resistance of the turn signal lever as instructed in the FSM and it seemed to all check out so I think no wires are broken in it.
• Small vac line at servo sticks to my finger when pulled off servo so it has vacuum but I’m not certain it’s enough. Any recommendations on a vacuum measuring device? All AC conrtrols work and reservoir seems to hold vacuum.
• I have also plugged off the large vac line at the servo to eliminate the brake dump valve if it was the leaky culprit
Also, if any one has a spare sensor and bracket for the clutch petal on a manual transmission I’d love to buy one.