92 Maxima. The **** on the dash to move from heat to AC won't go all the way over to AC. I can move it maybe a quarter of the way. I get a little bit of cold air out of one of the vents. Did some searching on the forum and found some info about there being "some resistance as you put it into hot or cold. References a "bleeder door". This sounds like it might be my problem. Where is the "bleeder door". How can I get to it to see if that is the issue/repair it?

Also found information advising "remember our cars have a heater valve which is on the firewall and has 3 or 4 small vacuum lines that dry up split and or fall off its purpose is to close the heater hoses flow into the core and airbox when you climate control is on full cold". Where exactly is this located on the firewall so I can see if that might be the issue?

Any other advice? Thanks in advance!!

 

In my experience, the problem with the slide lever is nothing behind the scenes like a blend door or anything like that.

The problem is that the actual plastic "rail" that the lever itself slides against gets worn out and distorted (or even broken) over time and effectively prevents the slider from moving all the way over. This "rail" is itself built into face of the climate control unit, and if it is so distorted or broken that you're having these problems, you basically need a new climate control unit.

I don't remember if the "rail" issue is visible in-car but it might be if you pull the ***** off of the slider. It's been years since I messed with it and realized that's what the problem was. I might have had to pull the outer facade off the climate control unit or look up underneath it to discover it.

I would put money over this being the problem over a mechanical issue with the heater valve. I've owned 5 3rd gen Maximas over the past 15+ years and all have suffered with the above problem to some extent or the other, and none have ever had any mechanical problem with the heater valve.

 

I had one instance here the cable broke free from the clip that secured it at the heater core, thus allowing the cable to slide around and not fully move the door back/forth. I don't recall if the clip broke or just come off. It was an easy fix. I would check that end of the cable first - before tearing into anything. I can't recall how visible it is with the glove box in.

 

Like James said it's very common and I've found its easiest just to replace the unit.

 

I've had to replace my climate control unit for the very same cause James explained. Junkyard unit solved my problem.