Heater control valve question

[east302]

First, are both heater hoses getting really hot? They should both be hot.

There is a temperature door actuator that rotates a damper to regulate flow to the heater core.

You must be registered for see images attach

The actuator is kind of behind the ashtray, pull the glovebox to see it. It's in a crappy location. It's #3 in the diagram...

You must be registered for see images attach

You must be registered for see images attach

It will have a round notched dial on it that serves as a position indicator. As it gets a signal from the a/c control panel, the dial will rotate as the actuator turns the air door. Turn your temperature dial from hot to cold and watch to see if the actuator dial rotates.

If it doesn't, it could be a bad actuator or no signal from the control panel.


Sent from my iPhone using Tapatalk

 

[lowreese26]

Yes both heater hoses are hot. The actuator that you are referring to, is this the blend door actuator? I will look when I get off work. Would that be why I always feel air coming out at my feet, even when I have the selector set to face? Also I’m not sure if this would be a factor but my truck doesn’t warm up to the same temperature as my previous gmt400’s do. I’m not sure if this would be a thermostat issue or clutch fan. Kinda leaning towards the clutch fan, as I’ve had a stuck open thermostat and it has always stayed super cold. This almost gets to temperature. It runs about here.

You must be registered for see images attach

 

[east302]

For the temperature, you'd need to put a scanner on it to see what the Coolant Temperature Sensor is reporting. This is the sensor right by the thermostat and is the temperature that the computer uses for engine controls.

The gauge is fed by the temperature sender which is near the driver side exhaust manifold. The low reading on the gauge could be a bad cluster or bad sending unit if the coolant temperature sensor is reporting a normal temperature.

There are three dampers for air flow: temperature, recirculation (above the blower) and the one by the gas pedal that controls floor-panel-defrost air flow.

Check the linkages on the one by the gas pedal. See if they are intact. See if they (and the dial) rotate as the panel is changed from floor to panel to defrost.

No heat would be a different actuator...the one behind the ashtray is the one that diverts flow over the heater core.

It sounds like you have either two bad actuators or a bad control panel.



Sent from my iPhone using Tapatalk

 

[lowreese26]

I have recently changed out the control panel. I will check the actuators.

 

[lowreese26]

Are both actuators the same thing? If I need them then order 2?

 

[east302]

Pretty sure that they're the same part, but check RockAuto.com and see if there are different options. I think the mode and temperature would be the same (they adjust to multiple positions) while the recirculation door would be a different type (two position only--open or closed).

Do neither one respond (rotate) to the control panel dial settings?




Sent from my iPhone using Tapatalk

 

[east302]

Here are the diagnostics for the temperature door actuator.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

Connector C3 on hvac panel...

You must be registered for see images attach

Sent from my iPhone using Tapatalk