HI Ron Again
Do over. Re-reading your last post I see you say you have no signal to the pressure switch. How did you check this and what did type of signal did you look for? You should have battery (B+) voltage (12volts) at the low pressure switch. If not then either the push buttons (PB) are bad or the Evaporator Temperature Regulator (ETR) is open or fuse 10 is blown since that is where the PB get there power. The ETR should be located in the heater box just to the right of the gas pedal. Check for B+ on the Black/Red wire of the ETR if none PB is bad. If power is going to it but none on the other wire ETR is open and needs replaced.