2000 tl a/c fan blower and compressor

My 2000 tl A/C blower fan started working intermittently then finally quit. Fan has been checked and works. However the fan will only work if grounded to the chassis and not through the normal fan ground wire. Also the A/C compressor will only run as the engine is starting then it shuts off. Any ideas? Car has been taken to a mechanic and they have no idea. It's really hot in FL. Thanks.