For the past two days ( both days never less the 50F outside ) I have not used my A/C
at all ( not even for window clearing ). I also have not used the HVAC system ( no fesh air fan / no heat )

Above the passages feet I assume the compressor lives because I am seeing frost there. I am not using the A/C why is this happening.

It seems wrong that the compressor will run without A/C on

HELP

 

the compressor is mounted the the engine block under the hood. Are you sure you are seeing frost? that's nearly impossible.

 

i believe there is a temp sensor at the evaporator that regulates how cold it can get, this possibly is bad

#19/20

 

correct, that was my initial thought, but he says he is not running the a/c. It would only be possible if the thermostat is bad and the compressor IS running. Maybe the a/c is running without you knowing it. check the compressor clutch to see if it is engaged while the engine is running.

 

> Yes its frost
> No ths AC is not on
> I seems like the clutch is stuck "on"

>"Maybe the a/c is running without you knowing it. check the compressor clutch to see if it is engaged while the engine is running."

I am going to pull the fuse this weekend an check.

This is also probably why my battery died over night ( from full change to zero ). I guess the clucth kept drawing power all night

 

try pulling out the compressor clutch relay. that is probably sitcking closed and keeping the clutch engaged. that will drain the battery. run the car with the relay out and it should not be engaged. replace with another relay from another circuit on the car and try it. if it fixes it, then replace the a/c relay with a new one. that should fix the problem unless it's in the a/c controls that are staying on, but all that should go off with the ignition switching off. I have had fan relays stick and run the fans until the battery died. the a/c relay is probably the same type relay if I remember and it may be stuck on. let us know what happens.

 

Update - I pulled the fuse (...heat ... A/C Clutch) ... No more battery drain / no compressor on !. I will check the relays this weekend. Thanks....