• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Cruise control circuit testing

nicpaige

NAXJA Forum User
Location
Ohio
I have a 2000 XJ and I added cruise control to it a couple years ago. It has worked flawlesly until I swapped in a new motor. Everything checks out mechanically. No air bag light, horn works fine. Cruise dash light does not come on. Can anyone give me guidance on how to check the switches and circuits? Also what wires from the ECM control the cruise?
 
do you have a check engine light? even with the light off it might have a code stored for the cruise control. also did any dash stuff get removed with the engine swap?

check all connections to the cruise control servo and that it is getting a vacuum.
 
connector 3 pin 32 is speed control switch signal.
connector 1 pin 4 is ground for the switch.

its a resistor switch so it changes the resistance for each button.
 
connector 3 pin 32 is speed control switch signal.
connector 1 pin 4 is ground for the switch.

its a resistor switch so it changes the resistance for each button.

Should I be checking for small voltage changes or resistance changes on pin 32? Also will it show a change with the car just running? I figured it would have to be running above 35mph before the switches would work on the steering wheel?
 
i would guess that it would change the voltage. i have never tested that. the ecu should always get the inputs from the buttons. just ignore them is speed or something else cancels it.

i would also make sure your servo has a good vacuum supply and that it wasn't damaged in any way.
 
Back
Top