Vent air is warm (1 Viewer)

[Riley]

I was out for the first time in my new 80 today and I noticed that the fresh air from the vents is warm (unless I have the AC on). TO be clear it's warmer than the air outside.

My guess is that the air feeding the "fresh air" intake is getting "preheated" somehow from the engine compartment. After running for 10 minutes or so it cools down ( i think). My other idea is that the control for the rad hot water doesn't shut off correctly.

Anybody ever notice this ? Is it normal?

 

[Rogue]

I notice that too. Just leave the A/C on all of the time.

 

[landtank]

Same here, it is especially bad if the truck has sat in the sun for a few hours. I wouldn't concern myself with the temp control as that usually will effect the air temp from the AC as well and it wouldn't cool off after a while, it would remain warm all the time.

 

[Seminole]

Check your heater control valve. Even with the A/C off and fresh air open, it can still affect the incoming air temp. There is a post a couple of weeks back on the procedure to check it. The FSM doesn't cover this in any detail (at least for a 91). If it is bad it is only about a 55-70 $ part.
HTH

 

[cruiserdan]

Condition normal. It is not possible to completely stop coolant flow. In addition the instrument panel heats up and so does the air intake system. That being said, sigfificanty warmer than outside air could indicate a mis-adjustment of blend doors in the heater assembly or a heater valve that is bypassing more coolant than it should. You will notice when moving the temp control from hot to cold that the temperature changes quite rapidly. The reason for rapid as opposed to gradual change is the blend doors inside the heater box. These doors open and close to divert air around or thru the heater core as required.


Dan.

 

[DLJ]

Dude ours is blowing warm all the time that the ac is not cranking.....man its gonna be great in the winter time......I thought it was just the f-ed up Auto Climate control's version of global warming......