So, here's my spin on what the problem is. There is no such thing as no heat in a 350z. The fresh air setting provides outside air to the dash vents or to the floor, but it passes through the heater core. There is no setting that can bypass the heater core. There is no separate path that bypasses the heater core. The heater valve never completely stops hot water from entering the heater core, so you always have a small amount of heat from these vents. This is either a design flaw or a leaking heater valve. The result is the same. As in all modern cars, is you set it to defrost, the AC comes on.

 

6 year dead thread bump on this one. Guess you dont look at last post date

 

Nope, I don't.

 

It happens, no hate here

 

No problem. I was searching the subject and didn't see an adequate response.