1982 300D a/c woes
 

Well, the A/C problem is that it does not come on instantly. Sometimes, it comes on instantly after I press the compressor button, or turn the car on if I left the switch on, other times, it takes about 1 or 2 minutes for the A/C to engage, sometimes, I will have to wait 5 or 7 minutes for it to engage. Why does it take so long for the A/C to engage? I just got it recharged last wednesday, and I took a look behind the glove compartment today, and the vacuum actuator moved and I heard hissing and stuff, but the air did not come on for a while.
-Joe

bump, because this is very annoying

C'mon ya'll, LOOK HERE!!!
 

my last bump, after this, I'll seek help for this problem elsewhere if someone doesn't have a clue here

Is the delay for the compressor only, or the blower fan, or both?

I believe its the blower fan only, because I think I can "feel" the compressor working when I press the button. I'll check later on the ride home today.
-Joe

Try hitting the "defrost" button on the far left of the climate control unit. Defrost automatically selects the highest on the seven possible fan speeds. Sometimes this will get the fan running, then you can select another mode. If this works, it could indicate a bad (poor, but not broken) connection in the CCU. The blower control relay is another possible cause. Could be the fan motor. Check for voltage at the fan motor connector when the fan should be "on" but is not. Sometimes the fuse contacts get corroded and cause this type of problem. How many miles on the car?

I have noticed whever I hit this bump on this bridge on the way home from school, or church, the a/c will come on. I will have to always go over this bridge in order to get home, no matter if I take different side streets to get to the bridge, resulting in different arrival times, if I drive over the bridge, the air will come on, so I suspect something might be loose or whatnot. Also, I noticed when I change the temp from MIN to any other setting, the air will stop coming from the center vents and start coming out of the defrost vents unless I turn the temp to MIN only. What's behind that?
-Joe

The CCU closes off the center vents when it thinks that it is in the heater mode. Only cold air should blow from the center vents. From your latest comments, my bet is a bad connection in the CCU. Some forum members have reported that resoldering some of the connections between circuit boards in the push button unit has solved this type of problem.

If the blower works when you hit the bump, it's the brushes. If it changes modes, there are bad solder connections in the pushbutton unit OR you have loose connectors on the pushbutton unit or on the temp sensors.

Peter

I had the same symptoms, but it was not the brushes. The blower motor was not getting power. The problem was in the CCU. It could be the brushes. That's why I previously suggested checking for power at the motor.