Hello,

I am having an issue with my heat output on my suburban. The heat output is very low when the dial is cranked to all the way up (high heat). I verified that heater core hoses are both hot to the touch. The coolant is full.
Not sure where to to go from here. Actuator or Heater core??

Any help appreciated.

 

Is the air VOLUME OK or not?

Heater core should be hot if both inlet and outlet are hot, if air flow OK makes it seem that air deflectors are either allowing cold outside air in, or air is bypassing the heater core. There are like 3 actuators under the dash that control this stuff.

 

Volume of air is fine. I figured it was the actuators. Just not sure which one controls the air over the heater core.

 

one thing to do is find the actuators and put your finger over the hole that moves the flapper doors and figure out which one isnt working. should be down on the passengers side floor