PSA - Evap core freezing

Been dealing with this problem for about 2 months. A/C starts out fine, but after a short period the air flow drops dramatically. The fan always seemed to be operating fine at all speeds too.

Went on a 290 mile trip last week and experienced the same problem, as usual. So I set the A/C controls to outside air, A/C button off, to de-ice the evap core. It didn't work, and what little air was coming out of the vents was still cold. Pulled over to gas up and popped the hood, just to take a look. By chance I saw the damn compressor running. I stuck my head back in the truck to make sure the A/C button was set to "off" and it was, which was really weird. Swapped the A/C relay for the fog light relay, and it cured the problem completely for the rest of the trip to my destination and back.

Looked at the relay under a magnifying glass and honestly could not see any problem with the contact, so I don't know exactly how it failed. But it obviously did, because it would not allow the compressor to ever cut off or cycle.

So if you have an evap core freezing problem, try replacing the relay. It may save you some money.

 

That was a great catch!

Good work!