A/C suddenly started blowing hot air

Good afternoon.

Did you check for power to the clutch relay? You should have two wires with power.

Also, check for power to the high and low pressure switches.

Roy

I checked for power to the clutch relay and it was showing 12 volts on one terminal. Can you advise where on the diagram that the high and low switches are?

As you can see in the diagram, one power comes from the ECM power relay. The other power comes from the fuse block from the fuse listed.

You need to get two powers to the relay first before moving on to anything.

Roy

Sorry for the confusion. I have power to both terminal 1 and 3 on the relay.

If I am getting 12 volts by putting my voltmeter on pin 1(86) and 2(85) when the vehicle is running, does that mean that both the high and low pressure switches are working properly since the PCM is supplying ground to terminal 2(85)? I tested the relay by applying power and ground to terminals 1(86) and 2(85) and the relay is clicking(switching).

No, the fact that both are 12 volts tells me there is no ground. If there was a ground, then you would have 0 volts.

By testing, you are creating enough ground to make the relay click or activate.

The PCM looks for inputs from the switches before it will ground the control side to turn on the compressor.

You will need a scan tool from here forward to see if the PCM is seeing the inputs from the switches. If it does, then the PCM is bad. If it does not then either one or both switches are bad or you have a wiring issue.

Roy

What is the best way to test the low and high pressure switches?

You need to check for voltage on both sides of each switch with the engine running and the AC on. There should be voltage through each switch. Back probe the wires to check for voltage.

Roy

Thank you. The Ford low pressure switch has three wires.

Power, ground and a signal wire. Measure the voltage on the wires.

Roy

I believe I have found the problem. One of the wires has a stripped cable(bare wire showing) and mangled

Yep, that will do it. Try and get a new pigtail. Parts stores sell pigtails of all kinds.

Solder and shrink wrap the wires together.

Roy

Done and A/C is blowing cold! Thank you for your help and especially your patience, I could not have done it without you!

You are welcome. Glad to help.

Roy