I have a 2012 RAM 3500 Laramie Longhorn single rear wheel.
I was having issues with the dual climate control in February of this year.
It would blow nice and hot on the passenger, but on the driver's side, not so much.
I ended up pulling out the HVAC box and replacing the heater core.
While in there, I checked all the different blend doors, mode doors, and recirc doors, and none were broken.
I did find some .22 bullets that had fallen through the defrost in the box, causing the blend doors not to open all the way.
I checked all the door actuators while the box was out and replaced the one that sits next to the firewall when the package is re-installed.
Boom, problem fixed, so now fast forward to summer.
The A/C air is nice and cold, but the blower doesn't seem to be blowing as hard as it should.
Last night I started digging into it, and I checked the resistor, and it seems to be functioning correctly.
I connected a test light to it and turned the dial, and the light dimmed and got bright, so I assume it's working correctly.
I listened to the blower motor, had my wife keep clicking up the fan speed, and noticed it's at max speed on the second to last click.
I believe there are five clicks to high speed. It maxes out the blower at 4.
I pulled the blower motor out, and it looks new.
The resistor and blower motor are Denso parts, so I'm pretty sure these have been replaced before.
I have an auto-scan tool, and nothing is giving me an indication of a problem.
I also noticed that the recirc door only opens when I switch to defrost.
It will not turn on or off from the button on the dual climate control panel.
I thought the actuator motor could be bad, so I connected my scan tool and commanded the recirc door open and closed, and it works using the scan tool but not when I pressed the button on the control panel.
I may have an issue with the actual HVAC control unit.
I just wanted to get another opinion, so thanks for taking the time to read this.
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