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Went for a drive today on a sunny 110F PHX afternoon.  Cooling system worked well in traffic and no overheating problems. 

I have an upgraded R134 system from Quella, so it has an extra row of coils on both the evaporator and condenser. AC was relatively cool but definitely not the best, so I probably need to add a 1/2lb of R134 soon.  I originally filled it with 2.5lbs per their recommendation.

When I got home and parked in the garage, I noticed the condenser fan continued to run after I turned the AC switch off.   I have the 3 pin AC switch that runs anytime the AC is on.   I unplugged the condenser fan connector to stop the fan.   I went back out a half hour later and plugged the condenser fan in and it continued to run.

As a side note the condenser fan has been working for a couple of months now with no issues and turns on and off with the AC switch as it should.

I'm thinking the AC switch has failed and is keeping the fan on?

Any ideas?




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You CAN get the 134 temp down to almost r12 temps. R12 will bottom out between 36-37F. 134 you can get to 39 or 40,

My a/c condenser fan has always run about a minute after the engine is off. I never thought twice about it as a result. I thought that it was just another Pantera specific quirk?

ONLY 110 huh? Definitely refreshing.

The thermistor (thermostat for the AC) with the knob on the front panel area near the radio controls a relay (maybe relays) for the AC compressor and the fan in the engine bay.  When turned completely counterclockwise it turns off the both the compressor and the condenser fan.  That knob can be stubborn to turn off when twisting counterclockwise.  Make sure you actually feel it clunk off.  Try clunking it both on and off.

I believe the problem has been solved and will know more tomorrow once my battery recharges overnight.

I confirmed the AC switch was working as @stevebuchanan mentioned by doing a continuity test on the switch as well as a test light voltage check.  Switches on an off as it should.

I remember when installing the new AC switch the wiring didn't quite match the late model schematic.  The previous owner had a wire spliced in the harness which I thought was due to a bad connection that had bypassed.

After pulling the relay panel down from under the dash I noticed the B/BK wire was jumped from the output of the condenser relay to the input of the condenser relay.   This was basically shorting out the relay and keeping the fan on constantly. 

It is strange that even after unplugging the condenser fan that it ran my battery down over night.  Based on the schematic it was probably creating a back feed situation and loading something else down to pull current.

PHX should be a balmy 115F tomorrow so should be a good test.




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