Diagosing heater problem? Blend door or?

[PaulBinCT]

Hey folks... What a great forum! Awfully glad I found it!

So, I have what seems like the common Explorer heater dilemma. Of course, now that we have a cold snap, my heat stopped working (2002 Explorer). My problem is 2 fold. First, in a desperate move to get heat while away from home, I followed a YouTube tutorial and reached around behind the glove box and tried to get fiddle with what I misunderstood to be the blend door, in the course of which I knocked off the linkage, not to the blend door of course but, I believe, from the solenoid that controls where the airflow goes. When I move the control from off to the various positions, I can feel the linkage move but the "far" end has come off. So, my first question of course is... how screwed am I? I intend to tackle this again in the morning and the first order of business will be figuring out how to reattach this. I'm praying I don't have to remove the entire dash

The "bigger" issue is trying to figure out what the heat problem itself is... I've read a few threads here and I can't figure out if the issue is the door, the actuator or something else. The symptom is cold air only of course but when I turn the temp control back and forth, there is a change in the sound of the air flow so I assume the actuator is moving the blend door... or is that not a safe assumption? I'm assuming that if the actuator was shot, changing the temp control would have no effect, but maybe I'm wrong?

What I'm trying to avoid, aside from wasting money, is tearing it all apart, and finding out I don't have what's needed for the repair which would mean reassembling everything to where it's drivable to get the correct parts... and repeat.


Anyway, thanks in advance for any advice and for a great source of info!


Paul

 

[Exproblems]

I knocked off the linkage, not to the blend door of course but, I believe, from the solenoid that controls where the airflow goes. When I move the control from off to the various positions, I can feel the linkage move but the "far" end has come off. >>>>>>>>>>
The symptom is cold air only of course but when I turn the temp control back and forth, there is a change in the sound of the air flow so I assume the actuator is moving the blend door... or is that not a safe assumption? I'm assuming that if the actuator was shot, changing the temp control would have no effect, but maybe I'm wrong?
Paul

Check the web link below(Post by Essam) for the linkage issue you think you have and check to make sure all of the small, dash vent controller(actuators) vacuum lines are connected properly. There are 5 or 6 of them of different colors that come out of a multi-port near the firewall and they go to the actuators that open and close various dash vents. Look for them thru the glove box area by rolling the glove box down and out of the way. You may have to use a flashlight and a mirror to see behind the dash. In the web link photos, you may be able to see some of these vacuum lines I am speaking of. Also, when you turn the temp control knob from cold to hot and you do not hear a loud "clunking or clicking" sound coming from behind the dashboard area, your temp blend door actuator is probably still good. Hearing the loud clunking or clicking noise is usualy a dead give away of a bad blend door actuator. Since you stated you can hear the air flow sound change when turning the temp knob from cold to hot, I'd say the blend door is moving as it should.
Your heat loss problem could be from something else besides the behind the dash problems. Make sure your coolant is full in the Expansion tank, check that both heater core hoses are getting hot to the touch after the engine is up to operating temp with the heater turned on and set to hot temp. Both hoses should be hot to the touch, if not, the "heater control valve" could be bad. It is a valve that is connected into the heater hose line that runs near the passenger side valve cover on the engine. It is vacuum operated. A plugged up heater core could cause loss of heat as well. Make sure the vehicle is getting up to normal operating temp and the t-stat works as it should. You can find past posts on various types of problems or fixes by using the search box at the top of the forum. Just type a question into the search box describing your problem and include the year Explorer you have and it will pull up any and all past posts related to the description of your problem. Good luck.

http://www.explorerforum.com/forums/showthread.php?t=323586

 

[PaulBinCT]

That's all great info! Thanks very much for taking the time to reply... I'm convinced at this point that the blend door is working, there's just too much audible change in the air flow. So I'm going to (in the morning) look into a coolant issue. Just so d*mn cold to be doing this... Murphy's Law


Thanks again for taking the trouble to reply!

 

[Exproblems]

Thanks again for taking the trouble to reply!

No problem, good luck with it!

 

[kware1]

hi, can I ask a question on this topic? I just had an engine swap and now I only have heat on the driver side floor. For the first few minutes everything is fine, then after driving, I only have heat on the driver side floor and cold air blowing it the vents and passenger side floor.

The heater control valve is connected, but I'm wondering if it could be backwards or something. I didn't know to check the core hoses, I'll check those too.

I really think it's something in the engine compartment because I've found a few other things the mechanic didn't connect. i.e. evap lines