My on/off switch quit working. I could wiggle it, and if the light came on it would work when "set" was pressed. Then the "set" button quit working. I purchased a new switch. It's easy to replace. The 2 screws on the back of the steering wheel come out, then the whole airbag and horn assembly is removed. Make sure you take out the airbag fuse or disconnect the battery first. 2 Screws hold the switch in place, and it has one connector. This cured the on/off problem, but the "set" button would still not engage the cruise. I then checked the vaccuum line under the driver's side battery, and it was off (credit to TDR). I slipped it back on and everything is cool.
2001 2500 4x4 Quad, Leather, Westach Fuel-EGT-Trans-Boost, FASS going it tomorrow.