1999 2500 diesel cruse works fine sometimes but most of the time when you hit the cruse the light will not come on if you hit the cruse when first started the light comes on but goes off as soon as you stsrt moving and will not come back on.

 

Possibly a wiring problem. The buttons on the steering wheel just modify a voltage that the PCM interprets. If you don't have a service manual yet, download one from here, find which wires at the PCM are for your cruise, and see if you are actually getting the correct voltages (or anything at all) from the controls.

 

It's probably the wires, I agree.

 

I just went through this and it turned out to be the brake switch. And there is an adjustment procedure for the new switch. My brake switch had one of the two tangs that keeps it locked in place broken.

 

Here's my info on what I did.



https://dodgeforum.com/forum/2nd-gen...l-related.html