1999 Ford Expedition (5.4L)

I have searched but couldnt find the answer. I'm not getting power to the Compressor clutch at all. I have Checked the coolant pressure and it is fine. I have checked all fuses and they are fine. I replaced the AC relay as well and still no power. What else could it be?
I read about jumping the high and low pressure switches, but couldnt find information how you go about doing that. Can anyone help me with how you go about doing this? Schematics would be great too!

 

Define "fine". The system requires a minimum of 45 psi of refrigerant (coolant is in the radiator) in order to "make" the cycling switch. This static pressure varies widely depending on the ambient temperature.

The cycling switch is screwed into the top of the accumulator can. To check for an open switch, uplug the switch connector and jumper the connector with a paper clip to see if the clutch now engages. If it does and you have the minimum system pressure, then the switch is bad.

The high pressure switch seldom fails, but it can be tested in the same manner.

You may download a schematic here: http://www.mediafire.com/?cgynulfczll

Steve

 

Thanks for your reply. I will give it a try tonight and let you know. My mistake, I meant refrigerant. It is at 55psi.