I turn on the cruise control and when I touch the SET button the light goes out and nothing happens. Before this it started to accelerate and not stop till the fuse burned out. I replaced the fuse and the circuit turns on. I reset the ECM. I replaced the the entire cruise control module and both switches / fuse is ok. What is left

 

Welcome to the forum.
Sounds like a bad wheel sensor. Mine did that after a hub replacement under warranty and the new sensor was bad.

 

where is the wheel sensor located?

 

Behind the wheel. Usually mounted to the hub.

 

I have a similar issue. My 2005 4x4 Ram Hemi 5.7 Cruise Control will shut off at 5MPH. If the vehicle is stopped or going very slow I can engage the cruise control but right at 5MPH the dash light goes out and will not come back on unless I go below 5MPH. I have pulled the steering wheel switches and hit them both with Contact Cleaner. I have a Superchips Flashpaq tuner that I set back to factory settings and then retuned back with corrected tire size as I am running 285x50x20 tires all around. There are no DTCs in the system. I have heard wheel sensor, clockspring, rear diff sensor are all possible causes. This a vacuum-less CC so it is not a leak. Can a wheel sensor go bad and still not throw a code? Any troubleshooting tips are appreciated before I just start replacing parts randomly at a cost I don't really have.

 

Left front wheel bearing. The wheel speed sensor which is part of the hub is bad.