Hello,

I picked up a 2005 crew cab f-250 dirt cheap because it didn't have air conditioning. I sourced every nuts, bolt and piece to put factory air on it. I vacuumed and charged the system this morning, my pressures were good and blowing cold. However, my high side pressure got to 375 psi and the engine fan didn't kick on. (I chickened out and shut it down when the pressure got that high)

I have two questions for you ford techs out there before i start digging in to the wiring.

1 . What is the pressure the engine fan kicks on on these trucks? (I'm used to it coming on around 300 psi)

2. Since the PCM controls both the compressor clutch circuit and the engine fan, is there a different PCM flash for a truck equipped with A/C and one not equipped with A/C?

Thanks,
Nick