[c good]

you have an excessive "air gap" and/or a weak compressor clutch field coil. Very common on this vintage. Remove the shim under the clutch plate or get a new field coil. Field coils are impossible to find so you may have to get a salvage yard compressor and take the field coil off of it. Otherwise you'll need to get a a new compressor and open the system. Than requires evacuation and recharge. Pull the shim out first. Then go from there. HTh c goood

 

[c good]

Removing the shim reduces the "air gap". It basically brings the clutch plate closer to the magnetic field coil, giving it a better chance to grab the plate and engage the compressor. If this doesn't solve the problem then you've got a very weak field coil. Pull the shim first then get back to us for the next step if it doesn't solve the problem. HTH c good