1986 Corolla Condenser & Radiator Fan Constantly On

Hi, I recently replaced the compressor on my AE82 equipped with a 4A-GE engine as it was leaking R-12 gas. The mechanic flushed the air conditioning system and refilled it with R-12 gas. He started the car, turned on the air conditioning and both the condenser and radiator fan came on as per normal. Operation was normal with cold air come out of the a/c vent. He then shut the engine off.

However upon turning the key into the ACC position (engine not started), both the condenser and radiator fan came on. It only stopped when the key was removed from the ignition switch.

After leaving the car alone for 5 hours, I turned the key again to the ACC position. Now both the fans DID NOT operate. I then started the engine and switched on the air conditioning for 1 minute. After turning the air conditioning off while the engine is still runing, both the fans continued to run although the engine was cold (temperature gauge slightly above the "C" mark).

I shut off the engine and turn the key to the ACC position. Both fans came on again. Need your help to rectify the issue as I do not want to use the car with the fans continuously on - the fans will wear faster.

What is causing the problem? Is there too much pressure in the system or could it be due to a faulty fan relay or pressure switch? I was told these switches rarely go bad and the relay problem sounds odd given the fact that the fans only come on after the air conditioning is turned on and off immediately. Thanks.