What I have:
98 F-150

What I know:
My compressor will turn freely by hand
The fan blows out of all vents correctly but only on high
Knocking on compressor face while AC is turned on does not cause it to spin
Coolant is appropriately charged

Question:
Are there some basic troubleshooting steps I should take that might id the problem?
Could this be as simple as a blown fuse?
Have I missed another thread here that already adresses this?

 

Two separate problems:

https://www.f150online.com/forums/se...archid=5019695

1998 HVAC Schematic: https://dl.dropbox.com/u/75400642/19...0Schematic.pdf

Check the series circuit of fuse F5, the mode switch, the two pressure switches, and the clutch coil.

 

thanks for the diagrams. Q - can i short the pressure sensor just by the refrigerant port to see if i am low on R-134a?

 

the link for the osther issue seems to be no good - https://www.f150online.com/forums/sea...archid=5019695 can you repoint me please?

 

Instead of hijacking old threads, just start your own. Sigh....

 

Might get more information and an efficient response this way. You are not willing to assist? Sorry to distress you...

I was just looking for advice on how to test the pressure switch.

Let's get to the fix. Please? Sigh...

 

Your answer might also help brfinkes. It's called a forum for a reason.