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No heat in my 2008 Chevy 2500HD

Arthur_paul

New member
Joined
Jun 13, 2025
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4
Hey folks, I'm not getting heat in my 2008 Chevy 2500HD (6.0L, regular cab). The engine reaches temp and the return line from the heater core is hot. I went to replace the blend door actuator and it turns out, there isn't one installed from the factory, just the mounting stubs. All HVAC fuses check out fine, any idea where else I should look?
 
If its hot and there's no blend door actuator installed, the blend door might be stuck or just broken. Even without the actuator, the door should still move manually, maybe its jammed. Also, make sure the HVAC controls are working and that nothing's disconnected behind the dash
 
Thanks, I'll try reaching the door manually to see if it's jammed, I'll also double-check the HVAC controls and wiring behind the dash, I hope it's something simple and not a teardown
 
Thanks, I'll try reaching the door manually to see if it's jammed, I'll also double-check the HVAC controls and wiring behind the dash, I hope it's something simple and not a teardown
Have you reached out to your dealer about the blend door actuator yet?
 
Hey folks, I'm not getting heat in my 2008 Chevy 2500HD (6.0L, regular cab). The engine reaches temp and the return line from the heater core is hot. I went to replace the blend door actuator and it turns out, there isn't one installed from the factory, just the mounting stubs. All HVAC fuses check out fine, any idea where else I should look?
Thanks, I'll try reaching the door manually to see if it's jammed, I'll also double-check the HVAC controls and wiring behind the dash, I hope it's something simple and not a teardown
I'd check the heater control cable, it's probably broken, disconnected, or just seized up.
It runs from the temperature knob on the dash to the blend door lever on the HVAC box.
You should be able to see the lever move when you turn the knob.
If it doesn't, that's the problem.
What @oasis1 about the blend door getting stuck inside the box could also be possible.
Sometimes they get gummed up or the pivot breaks.
 
I'd check the heater control cable, it's probably broken, disconnected, or just seized up.
It runs from the temperature knob on the dash to the blend door lever on the HVAC box.
You should be able to see the lever move when you turn the knob.
If it doesn't, that's the problem.
What @oasis1 about the blend door getting stuck inside the box could also be possible.
Sometimes they get gummed up or the pivot breaks.
yeah, a lot of those older trucks with a manual temp knob have a cable that runs directly from the knob to the blend door.
That cable can break, get disconnected, or just get seized up from gunk and age. OP need to get a look at the HVAC box behind the dash and have someone move the temp knob while watching to see if that lever is moving at all
 
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