Auto Air Conditioning & Heater Repair: 1999 Ford F250 superduty A/C inop, jumper wire, fuse block

Question
This is a 4/4 and triton V-10. System is charged and have good fuses. Have power at cycle switch both sides. have power at compressor switch. Do not appear to have ground. Have trouble determining if ground is controlled by ECM via Relay or not. Also unable to determine what relays are what in fuse/relay panel.

Answer
Hey Joel,

I'm going to have to look up a wiring schematic for this question to give you a correct answer. But what I am sure of is that there is a relay in the circuit and you should be able to locate in the under hood fuse block and the owners manual should tell which one it is. You can test it by using a jumper wire across the constant power supply and the terminal that receives power. If you do that and it works its a bad relay. I will contact you with more info when i get the wiring schematic, so give me a day or two. Thanks for your patience.