Question about hot air flowing through vents
I have a'95 ST. There are a few times in the summer that I have my top on and am running my AC. I will push my heater temp control to the top and the fan control to the top, then turn on the AC. The AC kicks on and runs great. However, I notice that there is always warm to hot air (the outside air temp?) blowing through my heater vents while I am driving (moving) even though I have the heater fan off (fan lever pushed up). Is this normal? It's like I am trying to run my heater and my AC at the same time. I have resorted to pushing the air through my defrost vents to at least get it off my feet. This is the only D90 I have ever owned and don't know of any others in the area. If this is the norm, then ok. I have dealt with it for 3 yrs. and I still love my ride.
Any input would be great. Thanks.