Hello Y'all, want to see if anyone has had a similar issue to mine. When I turn on my A/C, the fan will turn on and the A/C compressor is engaged. Cold air is coming out of the vents. A few seconds later the fan and A/C compressor will disengage and hot air will flow from the vents. During the day it is a constant back and forth with cold and hot air. But, at night the A/C will be blowing cold at all times with zero issues. I have had the systems evacuated and recharged, and during the vacuum phase there was no leaks. I also changed the fan module, but the issue is still present.

 

Temp sensors good?
one on the front inpact bar, the other one next to the drivers lnee.
blend door issue?
These cars keep the heater core flowing, i bypassed mine.

 

Which temp sensors? The ambient temperature works, and shows the correct temp. However sometimes my air intake temp is a few degrees lower than what the ambient temp shows on the dash. I just verified the blend door and they are working normal no issue. Went through all the different modes, and pulling air from outside and recirculating. How did you bypass the heater core?

 

UPDATE

It ended up being the A/C EVAP temperature sensor. I was able to get access into the A/C EVAP coil from the passenger side. Removed all the motors, blower motor, etc. It is attached to the coil by a plastic zip tie like clip. Used long needle nose pliers, and removed the old one. Put the new one in, and the A/C is back to blowing cold air.

If you have a high end scan tool you can monitor the EVAP Temp, to determine if this is the problem. Mine was constantly dropping to 0, then back up to temp, then back to 0. This was causing the A/C compressor to turn on and off. It would also automatically switch from recirculating to pulling air from the outside.