I have a 2001 F-150 4x4 supercrew w/5.4L, it has 217,000 miles on it. I just ran down to the grocery store, 4 miles and it was fine, on the trip back I noticed the temperature gauge wasn't working, all of the other dash gauges were fine, but the engine was idiling at 1500 rpm in park. In the last two days I drove it 570 miles from Albuquerque to Carlsbad and back with the AC on and all was fine, last weekend I was moving my son into his new place and I went to start the truck and it was DEAD. The relays were clicking, even after removing the keys, all electric was gone. I ran out and replaced the battery and all was fine again. I don't know that any of this is related to my current problem, but who knows? With such high mileage I wondering if I may be fighting a losing battle, or hopefully it's a simple fix. Anyone have any ideas?
Thanks for your help.