300cd 1982 makes a high pitched screeching noise when AC is turned on
 

AC stopped working and makes a noticeable high pitch noise especially on acceleration...blows warm to hot air. What should I troubleshoot first? Where is the compressor? AC was intermittant for a while...now it's hot as balls.

Thx

Seized compressor? I think on an 82 the compressor is low on the left.

I'm a neophyte...How do I check the compressor?
 

It still blows air...just not cold air. Thx.

Look at it with the engine running and see if the compressor is turning or the belt just slipping. The blowing of air is independent of whether the compressor works or not.

open hood, start engine, have somebody sit in car and put on the a/c look for the noise...
if the belt spins, but the compressor does not you have a seized compressor.
to verify you are looking at the compressor, look for the metal line that goes in front of the motor and follow it to the compressor.

watch out for your eyes. when my compressor seized the belt snapped and broke a blade off the fan. wouldnt want that to happen with your face in there looking around.

Mine did that as well, thanks to the clutch/pulley bearing going out. It loosened up enough to allow the belt to slip and make the thing hot enough to boil water off.

You'll either be opening your checkbook or openeing your windows.

Sorry for your loss.

thanks guys
 

Actually, it blew kind of cold air today. No screeching anymore. Looks like there is 123R, but maybe not enough? What can I do on my own to service the AC without special tools? Maybe it has a leak. The screeching was more of a high whine. I'll have my wife flip the AC switch when I get home from NYC tomorrow night...at least rule out the compressor. Anyone follow Diesel Giant's resoldering plans for climate control? Is that the wrong place to go if all switches work despite lack of chill?
thanks again.

this could be as simple as a loose or greasy belt.