The buttons on the steering while just modify the voltage supplied by the PCM. PCM reads the return signal to determine which button you are pressing, so it knows what to do with the cruise. The entire system consists of the buttons, the servo, and the PCM. Servo is just a couple valves on a vacuum motor, that pulls a cable. PCM is the 'smart' part. I would expect that the cruise memory would get erased just as anything else the PCM has learned since the last time the battery was disconnected. Of course, we all know what 'assume' implies.

 

Dylan Cochrell
1999 dodge ram 2500 slt Laramie
Hey guys I've been trying to get my cruise control working for the past couple of months and have basically gotten nowhere... let me give you the run down of what I have done, and the specifics of my problem.
1. Cruise control light won't come on
2. Cruise on off switches seem operational but it wont set and like I said doesn't even turn on.
3. It looks like somone has been in the steering wheel assembly already because I'm missing my radio controls on the right side of the steering wheel, there is just a hole where they used to be.

-what I have done so far
1. Taken out battery tray and checked vaccum lines repaired one line that had been tampered with all ready.
2. Looked the vaccum pump over, seems operational
3. Replaced brake light switch
4. Checked the wiring in the engine bay - checked wiring on pcm. Couldnt find any shorts
5. Thought it might be the clock spring but my horn and turn signals all work. No airbag light or beeping indicating a faulty clock spring.


I honestly dont know where to go from here, if you guys could point me in the right direction or share some ideas of what it could be that would be amazing. I'm kinda just stuck rright now not knowing what to do next.

 

Easy to test the switches. You can download the service manual for your truck from here. Wiring diagrams are in section 8W. Cruise control switches only modify a voltage by a specific value depending on which switch is pressed. So, test resistance across those wires when you press the various switches, and see what you get, also, verify you are getting power TO the switches. Should be able to test it all without pulling the steering wheel. Just take the covers off the column. I do believe they use the "security torx" screws though.

 

I can say mine does not take a security but for the column cover