300D AC blowing hot
 

I have a 1980 300D with 345000 miles on it. the whole ac system has been replaced at one time or another and i feel like it is a vacuum problem keeping the thermostat from working. what cam I check to confirm or refute my theory? what color is the vacuum line that opperates the thermostat

Check my topic, (fuses and their spring clamps) from yesterday it may be of help.

The is no vacuum line for the thermostat in the A/C. There is a control amplifier and the temp wheel in the pushbutton control unit.