I purchased a 1971 Chevelle with factory air. The seller said the AC did not work when he purchased it and left it not working. AC system visually looks ok except for not belt on compressor. What step should I follow to find out if AC works and or troubleshoot AC?
Do I put a belt on and see whats happens, can I pressurize the the system with air tosee if compressor kicks in??? Please advise.

The first thing I would do is try to spin the compressor by hand. Make sure its not locked up or the bearing is going out.

You could hook up a gauge to see if there is anything in the system. At least thats more PC then pushing the schrader valve in to "check" it..

Whatever you do, do not get any refrigerant with "stop leak" in it.

.... and after doing the above checks see if your getting +12 volts to the compressor to determine whether the problem is electrical or mechanical.

The first thing I would do is try to spin the compressor by hand. Make sure its not locked up or the bearing is going out.

You could hook up a gauge to see if there is anything in the system. At least thats more PC then pushing the schrader valve in to "check" it..

Whatever you do, do not get any refrigerant with "stop leak" in it.


When checking to see if the compressor is free, first try to spin the pully that the belts ride on, without the key on. Then try to turn the clutch portion (very front of compressor) to see if it turns. If both turn freely then move on to your other checks.

I would follow the above and introduce a vacuum into the system. If the system does not hold vacuum, you have a leak. The leak could be almost anywhere. Fix the leak, change the dryer and the oriffce tube. Thoroughly clean the internal system with a flush to remove any old oil and contaminants. Vacuum the system down, add the correct oil and amount of oil for your refrigerant, add either R-12 or 134A in the correct amounts and that should do it. If you are not comfortable doing this, have someone who is help you. If you use a shop, make sure you use someone who is recommended to you. If you have original parts to rebuild, try Classic Air in Tampa, FL or Texas. Vintage Air has a website that has much information about the ABC's of A/C. Give it a look. Good Luck. Jerry

And if you need more help, this place has been very useful to me...
http://www.autoacforum.com/categories.cfm?catid=2