2003 TJ with no heat

[lomax0990]

Hello everyone, I'm new to the forum and as of a couple months ago a new Jeep TJ owner.

I know this topic has been talked to death, but as you can tell from the title, my Jeep has no Heat. Not long after I bought the Jeep a radiator hose busted. So at the time, I replaced upper/lower radiator hoses and thermostat. I also did a Heater Core flush as everyone seemed to suggest it should be done at the same time. When I flushed the heater core the flow seemed good and it was surprisingly clean with hardly (if any) dirt coming out of it. I got everything put back together but I have no heat. The problem is I don't know if I had heat before the radiator hoses blew, because I never thought to test it.

The heater core inlet hose is very hot going in, and it seems to be somewhat cooler coming out, but nothing substantial. So aside from a bad heater core, is there anything else that could be the issue? Any other steps to try to isolate it? I'm hoping maybe it could be something else because I don't want to tackle the heater core project at the moment.

 

[John Scoggins]

Since the inlet and outlet hoses are at approximately the same temperature it seems the heater core is flowing fluid just fine, I would check the blend door to make sure it moves when you change the temperature settings on the A/C / Heater controls.

 

[Chris]

Since the inlet and outlet hoses are at approximately the same temperature it seems the heater core is flowing fluid just fine, I would check the blend door to make sure it moves when you change the temperature settings on the A/C / Heater controls.

Yep, X2 to this.

If the blend door is stuck, it's either a vacuum leak or a broken blend door actuator.

 

[lomax0990]

Forgive my ignorance here, but how do I "check" it to confirm that may be the issue?

I just replaced the one on my F150, but it was easy to diagnose because it was giving off a loud clicking noise.

 

[lomax0990]

Or maybe it's worth just replacing since it seems pretty inexpensive, as the next troubleshooting step?

Sounds like it may be much simpler than it was on my F150.

 

[Leinhit]

I'm sure much simpler.. if you are curious you could take both the heater core hoses off and flush with running water and check the output...

Easy to check and will most likely confirm its your blend door...

Check you tube for vids on how

 

[lomax0990]

Can anyone recommend a model/part number for a replacement blend door?

The original appears to have a metal sleeve or gears. About the only replacement I can come up with is a Dorman that appears to be plastic and some of the reviews aren't great. I wonder about it's long term durability.