A/C High Pressure Switch

Im having a similar issue with my A/C and the engine fan running all the time while the A/C is on. The fan runs as it should when the A/C is off, however, once the A/C is turned on the fan kicks on and stays on until the A/C is turned off.

I replaced the high pressure switch but that did not solve the problem. Turns out my old switch was and is fine as I tested both switches with a multimeter. However, when either switch is installed I connected it to a multimeter and instantly after turning on the A/C the switch opens which is what cause the fan to turn on but it never closes again until 2-3 minutes after turning the A/C off.

I had issues with my A/C not cooling about 8 months again they I had the drier and expansion valve replace. Everything worked flawlessly till a couple of weeks ago when the fan began running all the time. What could be causing the high pressure to be high all the time. The system has not been touched since it was last fixed 8 months ago. Could it be a bad expansion valve??

 

Im having a similar issue with my A/C and the engine fan running all the time while the A/C is on. The fan runs as it should when the A/C is off, however, once the A/C is turned on the fan kicks on and stays on until the A/C is turned off.

I replaced the high pressure switch but that did not solve the problem. Turns out my old switch was and is fine as I tested both switches with a multimeter. However, when either switch is installed I connected it to a multimeter and instantly after turning on the A/C the switch opens which is what cause the fan to turn on but it never closes again until 2-3 minutes after turning the A/C off.

I had issues with my A/C not cooling about 8 months again they I had the drier and expansion valve replace. Everything worked flawlessly till a couple of weeks ago when the fan began running all the time. What could be causing the high pressure to be high all the time. The system has not been touched since it was last fixed 8 months ago. Could it be a bad expansion valve??

 

Not enough airflow through condenser, internal restriction in condenser or high side of A/C system are some possible causes. Need to get a set a gauges on A/C system and infared thermometer to check temps.

 

I am assuming you are referring to the ac turning on the fan. Or is the fan coming on when it should not with the ac off? When the ac high side, the one with the red cap gets to around 300, the fan will come on. Did you replace the high pressure switch?