93 500 Sel A/c Codes
 

My air recently quit blowing cold, though blower works fine. After recharging with R134a, pressure seemed fine to mechanic, though compressor wouldn't kick on. My MB indy said it could be a control module which senses engine speed.
Sensor value I get for refrigerant pressure on the A/C readout is OO. Is this from a bad sensor, the fact that the compressor is not running or does it HAVE to be the evarporator?

I think you emailed me . . .
 

this morning??? Maybe reading the a/c diag code wil help point you in the right direction.

If the a/c system took a charge AND CAN HOLD IT, then look into the pressure switch located on the receiver/dryer. It's that switch that lets the compressor start if it senses enough pressure in the system. It does fail and that's what happens. I'd check there first.

Thanks. It appears we're narrowing it down, because the system is definitely pressurized, I checked, which means evaporator is okay (whew!). Hopefully it is just this switch. I'll keep forum posted.