1500HD where on 60 blows cold but on 61 and above it blows hot. Does the same on both sides of the cabin, whether it is on upper or lower vents, or whether it is on Auto or Manual. Airflow is strong. The previous owner replaced the HVAC control module and I have performed a recalibration.

Ran diagnostics and received the codes below. Anyone else experience/solve this issue?

B3770 - Air Flow control 6 feedback circuit - Faulty Mode Actuator
B0164 - Passenger compartment temperature (sensor 1) circuit range/performance - Faulty Inside Air Temperature Sensor
B0510 - Output air temperature (sensor 3) circuit range/performance - Faulty Output Air Temperature Sensor

 

Hi Payner1018,
This is my first post ever so bear with me.
I have the same issue!
Doing some research it looks like it's a relay behind the glove box.
It's a BI##H to get to and I'm going to give it a shot, but for now I have either MAX fan or NO fan.
Even with A/C the low fan setting cycles the compressor but not the fan.
I installed a new fan/motor so it's not that.
Just my .2 cents but it seems like a common issue from what I've seen.
Hope this helps a bit!
Pete.

 

My fan works great at high, low, and in-between. My issue is with the temperature not blending but it does it on both sides. I'm going to start with the inside air temp sensor as it is the easiest of the items listed unless someone knows the fix.

Good luck with your issue. I have watched several videos and know of the relay you're speaking about.