The heat in my SE has never been great, but I'm going to try and get it right before this winter. I will of course bleed the system, but I noticed that with the outside air vent supposedly closed, I still get air coming through the vents. I found the cable that goes from the outside vent lever (left side of HVAC controls) to the flapper unde the dash to the right of the console was disconnected. So I hooked it up, closed the vent, but still feel cold air coming in. Anyone know where the other outside air inlet is? This could be why me heat **cks, trying to heat up cold air from outside. Can anyone set me straight on heater function?

 

Ahhh, welcome to my world... I think I've figured out why mine is doing that... But first, a story about how I figgered it out...
When we changed my heater core, we had to discharge the AC... When the mechanic went to recharge it, the button didn't work for the AC... No light, no AC... Well, when he took the HCU apart, he found that the connection was fubar'd... When he resoldered the connection to the button, it worked fine.
Recently, my recirculating air started doing the same thing, and ever since we changed the core, I've had air constantly blowing. I think that it's because of the same problem, the connections are bad, so the button doesn't work, and doesn't close the vents.
Before, when they worked, I could hear it opening and closing the vents... Now all it does is shunt the hot air to a different vent.

 

Looks like I'll be pulling the HVAC controls out. First I'll take a good look at the chilton to see what is where. I'd really rather not have to freeze my toes off for another winter!

 

my HVAC system works fine (apart from stiff temperature lever), but the Maxima seem to produce less heat on full hot setting than my previous car, a Galant. Is this because of the design of the car (i.e. they all do that), or is something wrong? I seem to remember that my previous maxima also produces less heat than other cars. There seem to be plenty of heat inside the engine compartment! More than other cars, even. I'm a bit worried about the upcoming winter, especially since people says it might be pretty severe. And here in Minnesota, severe means cold! Siberia-like cold! Brrrr....