So Im driving to work this morning, all interstate, and goin about 80 mph. When I was about 5 miles out from where I work I noticed it seemed as if I was slowing down, and sure enough when I looked at the speedo, my speed had reduced all the way to 70. I didnt press the coast button or cancle button or the break. This is where it gets even wierder, as im pressing the accel button on the steering wheel, my defroster comes on full blast, but the Air switch was off, and the Fan speed switch was all the way on low. What the hell did my truck do? I eventually got it to shut off, but I dont want it to happen again, any ideas?

 

Sounds like a vaccume leak. Probably had a line that was dried out and cracked and the vibration from driving down the road finially cracked it apart. Both the Cruise and vent controls are vaccume opperated. It could be the vacume acuator too but start by looking for a leak.