Hello everyone!

I have a 2004 Chevy Blazer with heater problems. The problem? no heat...

The cabin fans work, but blows ambient air. I have tried thoroughly flushing the heater core, but no luck.

Does anyone have any tips on where to start diagnosing this problem? Is this a common issue with these trucks?

Any advice would be greatly appreciated. Thanks!

 

It's possible that the blend door actuator is stuck in the cold position, this happend to me along time ago. The gear inside broke. Factory they come with a plastic gear, the new upgraded one has a metal gear to fix the issue. It could be many things but this is one thing you could check. U just drop your glove compartment and you will see it back there it's a tight fit, but do a little research and I know there is videos showing how to pull it out so u can open it up and check to see if there gear is broken. Hope this helps.

 

When the truck is up to temp, on the passenger side of the truck (under the hood) touch the rubber heater hoses to the heater core, see if they are warm/hot to the touch.

 

What did you flush your core with?