A/C Compressor kicking on with A/C off

[Arnezie]

Ok my a/c compressor is periodically switching on with the heat on. The A/C is off and its on defrost floor and every 20 seconds or so it engages. Is this normal?

 

[19963.4lsr5]

Yes a lot of car company's run the AC when defrost is selected.

 

[Arnezie]

Yes a lot of car company's run the AC when defrost is selected.

Thanks, :closed_2:

 

[Kenworth]

I'm thinking all ac system cycle on off when defrost is in use

 

[shootmymime]

It's not normal to be coming and going.
It wants to turn on then does not build pressure and shuts off. Then cycles again.

You have low pressure in the system and it needs recharged.

 

[kindred4x]

During defrost the AC compressor will cycle on and off to cool down the evaporator thus pulling moisture out of the heated air to prevent a fogging windshield. Same principal as why any refrigeration/ AC system have condensate drains and pans, a cooler surface will pull moisture(humidity) out of the air and condense to a liquid. Just like a cold can of your favorite beer that sweats all over on a hot humid day.

 

[19963.4lsr5]

It's not normal to be coming and going.
It wants to turn on then does not build pressure and shuts off. Then cycles again.

You have low pressure in the system and it needs recharged.

When it's below 50 degrees outside even a properly charged a orifuss system will cycle.