Climate control is putting out ONLY high heat!

[Dma251]

After finally tracking down the super-annoying squeak in my Pathfinder interior to the miniature fan that moves air through the interior sensor tube, I disconnected and removed whole assembly, sensor included.

 

Now it will only output max heat. Does anyone have any experience with this? I haven't pulled it back apart and tried to plug the sensor back in and see it if helps. I would prefer to have a fully manual hvac system anyway, and would rather not reinstall the fan and duct (again, I am speaking of the tiny one, not the main blower fan).

 

Any thoughts out there about this before I roll up my sleeves again?

[Terranovation]

Have you checked inside the evap box to check for leaves, twigs etc? There is a how to section called Prevent Fire Clean Resistor or something like that.

[Slartibartfast]

Leaves and twigs didn't remove the low/intermediate blower motor speeds. However, the resistor pack you remove to clean out the HVAC box (the one that sets fire to the leaves and twigs that accumulate there) is where I'd start. That's what gives you different speeds for the blower motor. The high speed setting bypasses it. Lower speeds run through various combinations of the resistors inside to limit current and thus fan speed. It's behind the glovebox.

 

I hear you on wanting the manual HVAC. My '95 (parting out) had manual, the '93 that I've almost got back on the road has auto, and I did vaguely consider swapping systems until I had the dash out and saw how much work that would be. It's kind of cool to see how all the actuators and stuff work, but moving a lever is much easier than tearing the dash out to troubleshoot that mess.

[Dma251]

I guess I wasn't very clear - it's high-TEMP heat. There is no blending going on. I'm wondering now if unplugging the thermistor that connects via tube to the little fan that was failing. Maybe I need to dig back in and plug the thermistor back in.

 

 

[Slartibartfast]

Ah, I see. Yeah, I would imagine no temp sensor would give the climate brain the impression that the inside of the truck is ludicrously cold. You could probably get away with running the sensor without the fan (might not be as reliable though), or splice in a little 12v computer fan to replace the squeaky factory one.