Hi there,

Just did a long road trip in my truck this week fishing. On my way home today I was driving through temperatures that where in the 30c and I had fresh air vent on with the blower on hi. I am confused why the air that was coming into the cab was cold, it would be colder on Defrost selection. If I turned the A/C on it would cool down a little bit more but not a ton.
I don't use A/C alot so I'm not that concerner about the A/C so much, just want to make sure I am not driving around with it on all the time because of less fuel economy.
Any help would be great, thanks

 

The AC will turn on if set to defrost mode. Helps dry out the air much quicker.

But the AC shouldn't kick in if the AC button is off. I'm wondering if there's a problem with the HVAC headunit. Not sure if there's a relay for the compressor clutch. I'll have to check the schematics.

BTW, won't see much of a difference between AC on or off with our trucks when it comes to fuel economy.

MikeyB

 

believe the clutch engages when its the defrost

 

had basically the same problem. the dealer replaced the compressor/condensor (?) to the tune of $1200. I too was concerned about the fuel MPG if only running the vent.

good luck.

david
socal