Heating problems

GUTZMAN

MEMBER
2015 CHEVROLET TAHOE
5.3L
V8
2WD
AUTOMATIC
40,000 MILES

AC was working fine then when it got cold “winter” we put it on the heater. It would not blow hot air. The velocity of the air works fine but I can turn it up to 88 degrees and it is normal or cold air. I did feel a tad bit of heat drizzle out on the driver side but wife’s side was still cold it would constantly be cold air but if I keep it on low velocity sometimes a little heat would slip out but when I felt the heat I would turn it up and it would go cold again. Tired of freezing checked fuses and all look good not sure what to do. I do not think my AC is working either now, but do not know for sure because it has been so cold outside all I want is heat.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
43,110 POSTS

Hello,

The heater and air conditioner system in your car is dual zone so the fact that both sides are not working leads me to believe you have one of two problems happening. The first check would be coolant level becasue if it is low the heater core will go dry causing the heater not to work. Here is a video to help you check the level.

https://youtu.be/GSE9skKnOgY

If the level is okay the next place I would check is the mode door actuator which controls the air conditioner and heater functions.

Here is a guide that will give you an idea of what I am talking about

https://www.2carpros.com/articles/replace-blend-door-motor

This guide can help as well

https://www.2carpros.com/articles/car-heater-not-working

Here is the blend door locations for your car (below)

Insert a 3/8 allen wrench into the actuator mode control cam interface drive gear (1), and rotate the mode control cam to the maximum counter clockwise travel position to set to the vent mode.

I have all of the actuators locations in case someone else needs them that visits this post.

Check out the diagrams (Below)

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken

Images (Click to make bigger)