02 xlt no heat no clicking

[johnmize]

hi i need some help i replaced blend door actuator last christmas i have no heat and no clicking fan works fine any ideaas thanks

 

[johnmize]

update i pulled the blend door actuator its ok any thoughts? my wife and kids are freezing

 

[kingdong6515]

ever figure it out? I have same issue and have entire dash out..

 

[johnmize]

it was low coolant probably leaking head gasket no obvious external leaks

 

[rrgone]

kingdong

Is it just a lack of heat, or both ac and heat? If it's just heat then definately check engine coolant level and maybe install a new thermostat. One other thing to think about is a stuck closed heater control valve. That would keep heated coolant from flowing through the heater core.

 

[sfbayjay]

In my previous Explorer (1994 model) I had the thermostat fail and stick in the open position during a very cold winter trip. Result was no heat, although everything else was working fine.

New thermostat was cheap and solved the problem immediately...

Hope it's this easy for you!

 

[kingdong6515]

Unfortunately too late for it to be that easy AC works fine just not heat. And seems to get colder the more I drive. Coolant level is fine. I think the thermostat is fine b/c the engine was always ok temp wise. And the temp gauge did move as the engine warmed up. I felt heat at at both hoses to and from heater core. Now I am doubting that I felt enough heat. I didnt know there was a valve that controlled the flow to the heater core, I thought most cars have constant flow through it. And the temp sensor was always in normal range so I ruled out the thermostat. I do hear a sort of click or just an odd sound when I am changing the temp adj button to hot which I assumed was the blend doors broken/binding up. But they look absolutely fine! I heard someone mentioning the actuators worked when tested out of the installed orientation but didn't work when they were installed. Either way, I bought two new OEM blend door actuators and gonna put them in while I have the dash out. Not sure what else to do before I put dash back on. May replace the heater core for the H of it but how likely is it bad alreaady on an '04?

 

[rrgone]

Yep, there is a valve that closes off coolant flow through the heater core when you switch on max ac. It's vacuum operated and is located in the inlet heater hose under the hood. You should be able to watch to see if it changes when someone switches max ac on/off. Other than that I would definately change the t-stat out. Cheap and easy and if failed open you probably wouldn't know from monitoring the 'temperature gage'. Let us know what you find out.

 

[kingdong6515]

I'll definitely keep you posted. Thanks a ton, your time is much appreciated.

 

[sfbayjay]

To second rrgone's post: when my thermostat got stuck open I couldn't see anything wrong at the dash -- temperature gage showed everything was in normal range, but still no heat...

 

[kingdong6515]

Thanks guys. Im definitely thinking its the heater control valve. My heater core is flowing but the outlet hose is definitely not as glaring hot as the inlet.