cruise control only works when lights are off or in the auto position and off .... anyone else run into this problem at all .... its an 06 scab f150

just don't understand that it works fine that it only works with lights off very strange ... its still under warranty and I can bring it to the stealership but I'd rather fix my own problem and be able to know these things cuz I'm a tech and I'd like to know how to fix the problem if I was to run into it later on down the road

thanks again hopefully you guys got some input

 

Locate Auxillary Relay Box 1. Under the hood, left fender.

Remove the 5A fuse (Clockspring Illumination) and see if that corrects the problem. If so, the fault is in either the clockspring or the switch assembly on the steering wheel or the PCM.

My hypothesis is that the cluster illumination signal (also used to illuminate the switches on the steering wheel) is somehow making it into the PCM and is confusing the computer.

Steve

 

thanks for the input ill try it and then hopefully it will correct the problem

 

Along the same lines, check the tail lights. I've seen taillight bulbs short out, so when the lights are on, it sends a 12V signal down the brake light circuit. Make sure brake and taillights work the way they're supposed to.