No ac

Make sure the voltage to the compressor switches on and off via the switch inside the vehicle. If you do, have someone turn on the a/c with the engine at idle. The clutch on the front of the compressor, inside the pulley which turns, should engage, or try to, there is normally a click. Does it click and engage or rattle then stop? A rattle to the clutch indicates the clutch has had it and can be replaced. If nothing happens there could be a problem with the electro magnet just behind the clutch which engages it. It could be a ground problem within the magnet or the magnet itself. The clutch and electromagnet can be replaced, usually, without removing the compressor if it is located in an easily accessible location. Determine what the problem is, clutch, magnet, or seized compressor then price out the parts vs a replacement compressor.

Thanks

the areal answer i this , if you don't know what is wrong the internet is going to confuse you much more . The way it was designed was the front unit is run in a daisy chain style hose configuration from factory for the front and rear units to use only one compressor. The front unit only will pump the refrigerant in the proper cycle . as soon as you engage the rear ac evap system there is a electro valve in the rear of the truck the open and now allows the refrigerant to also be pu,[ed from the front to the rear unit . They do this to take some extra strain off the compressor from pumping the extra refrigerant for years and wearing out the compressor . The rear Valve is a sticky monster and always has been . To replace it you will need to dump the system and change the valve after verifying it is receiving power and if it is opening but not cooling the truck could simply need a topping off , since the size of the system has more than doubled when you engage the second unit . There are a few different situations that can roll the non ac guy so sometimes its the best idea to find an honest ac person , use common sense and trust them . Go have a coffee while they work, no-one like the customer hovering over their shoulder asking questions . If we wanted to teach HVAC we would have went that direction and made the big money (hahaha). Ford systems have provided my family food on the table since 1985 , they work good for a while and always break , thanks Ford !! All the techs remember Black death ? What a retirement plan that was . Good luck and take internet info with a grain of salt .