Wouldn't be the first time I've been a contrarian, but IMO all climate controls are bad, but the one on my QX4 is worse than most. I've also got a thing about arrogance, I have a limited tolerance for it, and for some guy (probably a guy) in a cubical in Japan to think he knows how much air should blow where at what temp due to a single knob setting is incredibly arrogant. Which is what the CC system is.

Anyway, rants aside, I want to be able to direct air, ideally at different temps, but I know that feature (of German and other European cars since the late 60s) hadn't reached Nissan by 2003, but I want to direct air, where I want it to be, stay where I set it, and without the blower ramping up and down. Now I know said unnamed person(s) think I'm not smart enough to know what's comfortable for me, but it turns out I am. All manufacturers seem to be going that way, the we know better than you do what's comfortable view, but Nissan/Infiniti was ahead of the curve. I realize such things as stratified air or a thermostat are well beyond the realm of possibility, but might lesser things be possible? Like me controlling things with a form factor better than a dozen toggle switches looking like a 1950s race car? Or do I just have to restrain and not backhand it when it changes something else when I change one thing? And believe me, I want to backhand that thing when I change the temp and it changes fan speed and where air is coming out.

An example of the usefulness of stratified air. I was going across I80 across Donner summit one time some years back. A blizzard, heavy blowing snow. Road was open, car was even stable with the mandatory chains, but late at night. I needed the defrost set hot and lots of air to keep the windshield clear. And I had a trickle of cool (ok, cold, but just a trickle) of unconditioned outside air at my face to keep me awake at 2AM. This was in a '79 BMW. The 4WD of the QX4 would have kept me moving right along, right into a snowbank when I fell asleep.

I think trying to reengineer this might be more of a head banger than it's worth. Definitely more than a weekend project. Not sure where I'd even start.

mdmellott wrote: ↑

Thu Dec 10, 2020 11:29 pm

I think trying to reengineer this might be more of a head banger than it's worth. Definitely more than a weekend project. Not sure where I'd even start.

You're probably right, but it drives me nuts and I thought the question worth asking. Actually reengineering it might not be as difficult as not having it look like the dash in a 1950's race car. I mean toggle switches are easy along with a potentiometer or thermostat. But I was wondering if an earlier R50 chassis HVAC interface be more or less plug and play and come close to what I would like. Of course this is all for a truck that sees 4500 miles a year in 2.5 weeks and another 1500 in the rest of the year... It's the vacationmobile and far from a daily driver.

Mike W. wrote: ↑

Thu Dec 10, 2020 11:41 pm

Actually reengineering it might not be as difficult as not having it look like the dash in a 1950's race car. I mean toggle switches are easy along with a potentiometer or thermostat. But I was wondering if an earlier R50 chassis HVAC interface be more or less plug and play and come close to what I would like.

Now that you mention it, this could be possible with a control unit from a Pathfinder used to downgrade, so to speak, the QX4 control unit. The plumbing behind the control units on both are very much the same. Probably not a plug and play but it does look possible with a bit of work.
https://www.infinitipartsdeal.com/parts ... m=272_A002
https://www.nissanpartsdeal.com/parts-l ... am=272_004

You could put a fixed resistor on the Ambient sensor and a potentiometer on the Cabin sensor to fake out the system. They're both RTD (resistive), so fixing the outside temp the system sees should put the cabin temp in total control of what the system does. It won't help for stratified air, but it should "manualize" the system's responses.

A lot of discussion regarding the nav and climate control wiring in this thread, maybe it will be helpful or inspire you: update-removed-navigation-and-rewired-a ... %20control

I have the Pathfinder version below but I believe it has the same functions as the QX4 control. It does not give the range of controls as a BMW, but you should be able to put it in Manual mode so the fan is not automatically adjusted. Mine goes from Auto to Manual by just changing the fan speed.

My QX4 mode door motor went bad. I just removed the motor and move the door control lever by hand to where I need it. You cant move it while you drive. You have to stop and reach under the dash on driver side to do it. Page 28 on the service manual.