Been a long time since I have been here. My baby doesn’t come out much anymore. I have a 2002 I bought new back in the day. It has about 120k miles on it. I took it in the other day to have emissions done. I’m almost certain I used the cruise control on the way there. I took my Edge EZ off in a nearby parking lot and then had the shop run it through. When they were done I pulled out and parked nearby and had to do some work on my laptop. While I was doing this I was running the truck for the AC. While I was doing this, the idle went up about 400 RPM. I hit the pedal and it went away for a minute and came back. When I pulled out and got on the road the RPM would periodically go up and then back down, and then I did get dead pedal P0121 on the way home. I also tried the cruise on the way home and it was not working. I figured it had something to do with the deal pedal and codes so I didn't worry about it. I got a WVE Wells Vehicle Electronics APPS and installed and calibrated it to .52 volts. I have not put much time or miles on it but I have not had the dead pedal issue again and no codes. I think the dead pedal issue is resolved, but time will tell. I don’t think this is related, but the problem I have now is when I depress the “on” button for the cruise control, I get no light on the cluster under the odo indicating it cruise is enabled. These symptoms do not lead me to believe it’s a vacuum issue but I have checked all the vacuum lines and done a visual of all the wires in the steering column. They look fine, no hose problems, hose connector or hose cap issues, no electrical opens, shorts or wire issues. I replaced the clockspring and as a measure to verify I got a good clockspring, I switched over a known good clockspring from my 99 ram 1500. Same issue. I also replaced the brake switch. Still no go. I cannot get the cruise light to come on and I get no cruise control. I’m thinking about getting a scan tool so I can see a little more detail about what the ECMs are seeing or not seeing. I also see another diesel site has service manuals on CD so I may order that as well. I can’t troubleshoot the electrical circuits because my Haynes manual is more of a generic schematic and not a detailed wiring diagram. I am seeking advice any input would be welcome.

 

This may help and it may not. I bought my early 98 12 valve in April of this year. I did two 350 mile trips to Carlise PA wishing the cruise was working because when I hit the on button the green light did not come on. I searched and found a thread that said to check the light because sometimes the light goes out and the cruise is still working. For me to get my cruise working I have to hold the on button for 4 seconds and then hold the set button for 4 seconds and low and behold it works. No idea why but that's my truck.

 

Clockspring.....search it.

May get replaced as warranty since it operates the airbags-safety issue...

 

Common vac leak, must remove battery to fix. This controls cruise control.