Hello. Just purchased a 2008 F250 V10 Crew Cab with 64,000 miles. The truck has some electrical issues that didnt show up during the test drive/inspection. It seems that the HVAC head unit causes some interesting things to happen. The most obivous problem is that when you turn the climate control on and turn the fan speed up the CC will not work. If you turn the fan off but leave the HVAC control on CC starts working. At this point you can turn the fan speed back up and everything stays working. Not sure if its related but it also has the printer noise going on behind the dash which Ive read is the one of the blend door actuators going bad and the keyless entry pad will not accept a personal code(everything else works on it, factory code, lights up, two button lock). Any ideas or checks? Thanks for the help!

 

The only thing I can think of would be a grounding problem to the cab. I wonder if the engine has been changed or some serious work on it has been done, and someone forgot to hook the ground back up between the engine block and the firewall?