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?