have a few probs. with my 04 1500 5.7, the cruise control shuts off after about 55 mph. it wont turn on or anything, it works perfect under 55. also when I first crank it up (cold)the idle is screwy. It will go from about 600-1000rpms. up and down until I put it in gear, then it stays normal. My other prob. is when I turn the headlights off after I shut the truck off, they stay on until I turn them back on then off. I tried waiting a few minutesfor them to turn off but they wont.any ideas what can cause these things? Thanks in advance.