First I gotta ask, are you sure the relay you used was new from Ford or is known working relay?
Originally Posted by 210craig
I assumes that rules out the pressure switches.
No, the jumper is supplying power directly to the AC Compressor, bypassing the control switch's input to the PCM.
Test the pressure switch's as follows:
Pull the electrical connector at the Low Pressure Cycling Switch. Using a volt ohm meter check for continuity between the switch’s two terminals. You should read continuity. If not replace switch.
Next, check for continuity between the switch’s electrical connector terminal the Red with Yellow stripe wire and chassis ground. If it reads as open circuit either the High Pressure Cut Off Switch or its associated ground is bad.
If the above checks good, pull Mini Fuse #1 (10 amp in PDB under hood) and see if you still have power at the relay socket terminal in your sketch labeled “Jumper”. If you lose power with the fuse removed it is terminal 3.
The other terminal of your sketch labeled “AC” should be terminal 4. You can confirm this by checking with a volt ohm meter for continuity between this terminal and the A/C Compressor’s electrical connector terminal Gray with White stripe wire.
The other terminal you found power at should be terminal 2 from the PCM Power Relay. With the Key On, using a volt ohm meter, you can verify this by pulling Mini Fuse #8 (30 amp in PDB under hood) and see if you lose power at that terminal.
I believe if you look down inside the remaining two terminals with a flash light, one my be blank (no actual wire connected). The other with a wired terminal should be terminal 1.
Once you’ve identified the above, turn the key off and disconnect the battery, then the PCM connector. Reconnect the battery, then locate a purple wire at the PCM wire connector (PCM terminal # 41), a Pink with Yellow stripe wire (PCM terminal # 69), and a Black with Yellow stripe wire (PCM terminal # 86).
With the Key on and the selector control set to A/C, check for power at the purple wire in the PCM wiring connector. If power is present, proceed to next test.
Check for continuity between the Black with Yellow stripe wire at the PCM wire connector and the same color wire at the A/C low pressure cycling switch connector. If you have continuity proceed to next test.
With the Key Off, check for continuity between the Pink with Yellow stripe wire at the PCM connector and terminal 1 of the A/C Relay socket.
If all of the above checks good, the problem more than likely lies within the PCM itself.