I have a 2001 Ford F-150 and my a/c suddenly stopped working. At first I thought it would be the blower motor but I tested the motor and it worked fine next I moved on to the resistor which sure enough was rusted and needed to be replaced. However, that didn't solve my problem, the blower motor just isn't kicking on. I then went to the relay and replaced it as well. Still nothing happened, I am at a complete loss now and don't know what else it can be. Anybody have any suggestions? I thank any comment in advance

 

The blower motor is supplied power through the 'operated' relay contacts from a 40 amp fuse 105 in the engine bay box.
Either the fuse is blown or the relay has not operated. The speed switch is open or the relay operate power source is open.
That power source is fuse 24 on the dash fuse panel.
This fuse is only powered with the ignition to Run position so the fan cannot be operated unless the ignition is on.
No more to it than this.
For the circuit, see Haynes Manual page 12-34.
Check those fuses and/or use a voltmeter to test for the open location.
Good luck.

 

The Mark VIII Lincolns like the 95 I had was infamous for a loose connection in the short pigtail where it connected to the blower motor. The problem was so prevalent that the dealer kept those pigtails in stock. Not saying this is your problem. It could just be a bad blower motor.