I had the system recharged last week and it was working good up till now. Now the compressor won't engage when the system is turned on. I jumpered the low freon switch with no result. Fuse is ok. Where is the relay located for the system? Any ideas? Thanks Dan


1980 300D 225500 miles

Be sure to check power on both side of the fuse!. I had the same problem and found the fuse connection not making good contact in the holder and it caused the same problem of no clutch engaugement. I think your 300D has the temp control thermostat knob on the console. Check to see if there is power at the switch after checking the fuse. I think also the power is distributed by the vacuum relay switch as well so check to see if the a/c heat is switches over properly. Someone please correct me if I am wrong!
Regards,
Bryan