No Cold Air

[Merle]

I have a 2008 Sterling Acterra no cold air, Things I've done and found 1) checked and found compressor clutch not engaging 2) Reclaim Freon 134a , vacuum down system added oil and recharge system was found to be 0.11 LBS low. 3) Started checking for bad Hi and low pressure switch hi pressure switch is a 4 wire and I don't know how to test it. looked for fuses and relays but couldn't find in the fuse blocks (would be nice to have a wire schematic )

[Nacho]

Do you happen to know what is the equivalent model in America?

[AC_Chris]

It's a fairly common truck here in the U.S. A/C system looks to be mostly Ford. You would almost think you are working on a Ford Ranger, but the parts like the accumulator, blower motor, evaporator, etc. are all at eye level.

[AC_Chris]

Started checking for bad Hi and low pressure switch hi pressure switch is a 4 wire and I don't know how to test it.

You mention low pressure switch, did it test O.K.?

[Cornbinder89]

If I had to guess, it would be that it has a common trinay switch (Red DOT) and two of the terminals are for the fan override and two are for the compressor clutch (high and low cut-out)
If it has a STD Red dot wireing orange and yellow are for the fan and black and black with a tracer are for the compressor.