I have a 2001 Ford Ranger , 2.3 , 5 speed

Last year my ac had a leak fixed it worked fine, this year ac would not come on, clutch would not engage. I replaced the ac compressor with new , I am getting power on both plugs to the connection pins on a test light to ground to the compressor, should both pins have power? We did jumpers on the low side and the high side pressure switches and clutch still does not come on. There is a leak when we vacum down system that we know of , if the freon is low will that keep compressor engaging even if jumpered to bypass switches. Im not sure which fuses , and relays are the exact ones due to the different fuse diagrams out on the internet, but believe I have the correct ones. One of the relays feels very hot , I have also replaced them, Any help or direction would be helpful

this forum helped me before when I replaced the engine hopefully can again

thanks

 

The AC Clutch is an electro-magnet so it is just a Coil Of Wire inside, if you have 12v on one side then you will also read 12v on the other side, because it is just a coil of wire.


The 12v for the clutch comes from engine fuse box, fuse F1.25, 10amps
Yes it comes from the Clutch Relay in engine fuse box

Fuse F1.25-----------------AC relay-------------AC Clutch--------ground

So pull off the clutch connector and test that 1 wire(black one) is a good ground
Then turn on AC and see if the other wire(grey/white stripe) has 12volts
If you have a ground and 12v then system is OK
If compressor doesn't engage then clutch itself is the problem

Ford AC clutches did have "air gap" issues in the past
Google: ford ac clutch air gap spec

The electro-magnet needs to be close to the metal plate so it can pull it in and engage the compressor, if the "air gap" is too wide then it can't pull the metal plate in



The AC Relay's coil gets 12volts when key is on, but has no ground so stays open
The Ground comes from the PCM(Computer).
The pressure switches supply that ground

Ground------low switch----------high switch------------computer

When you turn on the AC, you are sending AC demand signal to computer, not the AC relay
Computer then connects pressure switch ground to AC Relay ground, relay closes and 12v is sent to compressor clutch

On the 2.3l engines with electric cooling fans the fan should also start when AC is selected, but if testing on cold engine that might not happen since computer also has engine temp sensor and if it shows cold then fan might not come on.
But if you warm up the engine and then turn on AC with engine still running you should see the fan come on, this would test that the AC Demand signal is getting to the computer and computer is grounding the Fan relay, so should be grounding the AC relay at the same time, both the fan relay and AC relay should "click" when activated, you can put finger on one and feel it.
Yes Relays can get warm when activated, they are passing higher amps