Rawze adrino setup

[Lonestar10]

Basically the Arduino does every thing but controll the HVAC fan and blend doors. I think the high pressure switch might be still connected to truck for engine fan maybe not but a properly coded Arduino with a temp sensor in the evap to control compressor on off based on temp of evap so it doesn't freeze over, then I'm sure you could decipher the signal from high pressure switch hook it to Arduino then set a engine fan on/off and emergency compressor turn off pressures in the coding.

IDK if there's a way to tell body controller to turn fan on with this setup. If you wire a 2nd activatable ground on fan solenoid the ecm/bcm might throw a code when fan activates but won't hurt anything.

So parts
Arduino
Wiring
Temp probe for evap
Coding
Reuse trucks HVAC sensors that are needed