I have an 06 lbz with 271000 on it. This past sunday coming down the highway on cruise control the truck felt like it fell out of gear and the Service 4wd System light came on and the 2wd/4wd high/4wd low light indicator was off, truck stayed in 2wd. 30 min later the service 4wd light went of and the Security light came on. The next morning drove 40 miles to work and everything was back to normal until I went on a 2 mile parts run. Went to crank truck up and it cranked up and ran for 2 seconds and cut off. Cranked up again with same result, two more tries with same results. Then I noticed that my rear power windows were not working but front windows were, also no power door locks and no power to the steering wheel controls. Had truck towed to shop, changed fuel filter, primed and tried to start. Truck cranked and ran fine for two days then it died again with the same symptoms. The very next morning truck cranked up just fine, drove another 40 miles to work and about mid morning lost power to windows, steering wheel, door locks while driving. Made it back to shop and check engine light came on for Thermostat stuck open and truck running cold (165*) from scan tool. Started checking all wires under truck, through fire wall, and under dash, also checked under front fuel panel. Found a 40 amp fuse blue in color powering stud #1 blown. I replaced fuse and tried to crank truck with no improvment.