1996 Aerostar with a disabled A/C system.

Actually I believe the relay itself is okay. I read that there should be power at pin 1, and pin 4 going to the relay and I only have power at pin 1. Now that I've figured out there is no power at pin 4 I don't know what to do to resolve this issue. Does anyone here know what I should check next?

Welcome to this forum! Your thread was renamed to explain the issue that you're having. Did you check to see if there's enough freon in the system? The low pressure cut out switch will disable the compressor if it's low on freon. Are the fuses good?

I just charged the system, so the pressure is good. I show continuity through the high pressure switch and power to the high pressure switch. The fuse is also good.

I've now read that there is no such thing as a high pressure switch, but whatever switch is on the canister is showing continuity. Where ever the power to pin 4 on the relay is coming from it's not working.

1996 Aerostar van air conditioner schematic diagram.

Here's a schematic of the circuit from my Ford software:

Thanks! The wiring diagram is a major help. I'd tracked one down on line finally. But the one you have posted here is a better one. Clearly whoever it was that posted the post I read elsewhere stating there was no high pressure cutoff was mistaken. Since I have power to the clutch cycling switch on the A/C accumulator, and that switch appears to be working, the problem must lie either in the wiring from that switch to pin 4 or the high pressure cutoff switch. I'll locate that switch and check for power to it, and determine if it is functioning properly. Thanks again!

The diagram shows that pin # 4 is connnected to the PCM, so check that as well.

I said I'd locate that switch, but I can't even see the front right side of the motor, much less see the high pressure cutoff switch. Like most vans, the Aerostar has a ton of stuff crammed into a very limited amount of space. I may yet take this project to my mechanic. At least I'll be able to save him some time by telling him what I've discovered. The dark green and orange wire runs from the high pressure cutoff switch to both the PCM and pin 4 of the relay, but I don't think the power to pin 4 is routed through the PCM. I'll try jumping power to pin 3 to make sure the compressor will kick in, pryer to taking the van to the mechanic.

Thanks again for the assistance.

I'm sure that the mechanic has the same diagrams as the one in post # 5, but I would print a copy just to show him what you've done until this point.