I've been troubleshooting the a/c on my 1991 F250 XLT Lariat 4x2 for a few days now. The blower is working, but is not pushing any air through the vents most likely due to a clogged evaporator (its covered in dirt and may be a little damaged so its not allowing air to pass through). Additionally the compressor clutch is not engaging. I read the wires going to the compressor and am not getting any voltage. I tried jumping the accumulator to see if it was a low charge keeping the compressor from coming on and had no luck with the power issue. This leads me to believe that the a/c switch on the console isn't engaging to send power to the system. Any ideas?

 

You already ruled out the accumulator, so yes, focus on the console and the compressor wiring itself. Replace the evaporator too.

Dumb question: Did you check any related fuses?.