Heater Blend Door Issue

[int3man]

Hi All,  Got in the truck to get the Christmas tree we are having our first good storm of the year in Northern CA.  So we drove with no defrost and foggy windows.  Reading the trouble shooting options the hoses are both Hot with the right being hotter,  no hot air blowing anywhere  If you turned off the fans and idled I did feel some heat but not enough to warm the cab.  Looking at  a trip to Seattle at Xmas time this isn't going to cut it. 

 

Is the Heater Treater still the hot ticket for this issue?

 

Thanks Cold in the Central Valley!!

Michael

Edited December 2, 2019 by int3man
Typo's

[Nekkedbob]

If it is the blend door actuator is the problem. It sounds to me you have a plugged heater core. I have had this on several vehicles and as a temp fix that has got me through the winter I did a back flush of the heater only. I pored vinegar in it and then flushed with hot water. I cant say this is a solution but has helped me. 

[JAG1]

I had the same problem. Don't know if its the blend door actuator or the piece that the heater treater rplaces. I got mine to work one last time on hot so it's staying there till I or MoparMan gets a chance to completely redo everything on the HVAC system. Last friday I smelled antifreeze when turning on the defroster so my heater core is going. Plus I got a leak in the evaporative cooler that IBMobile found.

 

My suggestion is to replace everything once you pull the dash to get in there.

    my replacement list;

    Heater treater

    evaporative cooler

    heater core

    new foam tape/ gasket to the clamshell design

    new condenser drain hose thru the firewall with a downward 90 outside

    lube all moving parts

    

I can always replace the blower and resistor later along with the blend door actuator from the outside of the whole plenum.

 

 

Edited December 2, 2019 by JAG1

[Hawkez]

Are you getting airflow through the vents?  I had a big issue with low airflow and my HVAC box was full of so much that air couldn't pass through.  You could remove the squirrel cage and get an idea of how it looks inside-stick your phone up there are record video.  Last winter I pulled my HVAC box, that was the best repair I have done to my truck.  I replaced the heater core, AC evaporator, squirrel cage, and the resistor.  I installed the heater treater piece, but mine was still in good shape.

[int3man]

Yes sir we have air just no heat.  Hot Water hoses.  Don't know how hot but as described hang on to the outside one and not the inner.

 

Thanks!

Michael

Edited December 2, 2019 by int3man

[int3man]

O.K.  Reached in between the door motor and the heater box.  I was able to spin the output shaft continuously.  So it is a toast.  I'll get it pulled out.  The Heater Treater looks pretty simple to emulate.  A Stepdown Copper reducer might just do the trick.  We'll see.

 

Michael :-  ) 

[JAG1]

Got any pictures so we can learn what your doing? I hope a simple fix for you.

[int3man]

Nope not yet.   Just getting into it.  This really Sucks!!  I tried a 1/4 flex socket with a bit in it and it bent too much so I'll try some tape tomorrow.  Post photos when I get it apart!!  Check out the Heater treater link below.

 

Michael :- )

 

https://heatertreater.net/dodge-ram-95-02

Edited December 15, 2019 by int3man

[dripley]

I used that in mine but the hvac box was sitting on my work bench. Very easy to do there not so while in the truck. I see they have gone up over the years. They were $25 back about 7 or 8 years ago.

[int3man]

O.K.  TOTALLY Weird now.  Finally got the back screw out.  Actually a friend did, I don't fit stepwells anymore. And the intermediate part was good and the servo motor was tracking unloaded.  So the last turn to cold the motor did not stop must be trying to shut the door and can't because it is hanging loose.  So we manually kicked the door to heat and I have a little heat but no large movement of air.  If I Kick it to max A.C. it blows Cold Hard, through the face vents.

 

Is there a way to flood the airbox to wash it out?  I know on the Megacab had a drain nipple that keeps the bugs out to eliminate the condensation from the A.C.

 

Thanks

Michael

Edited December 19, 2019 by int3man

[dripley]

There is a drain in the front right of the hvac box at the inner fender well for condensation to drain from. How much you can flood the box before it comes into the passenger compartment is beyond me. 

[int3man]

I'm going to try flushing the heater core back and forth, see if I can get crud out of it.  It was an Arizona Truck and probably never had the heater turned on.

 

Thanks Michael :- )

[Tractorman]

1 hour ago, int3man said:

So we manually kicked the door to heat and I have a little heat but no large movement of air.  If I Kick it to max A.C. it blows Cold Hard, through the face vents.

 

I think you are going to have to pull the dash.  It is sounding like the air flow through the heater core is mostly blocked, unless the blend door is actually broken and blocking the path through the heater core). 

 

The blower motor draws air from outside (through the cowling behind the hood) or from the interior of the cab (recirc mode).  After that air exits the blower outlet duct, all of that air passes through the evaporator core.  All of that air leaving the evaporator core is either diverted around or directed through (or both) the heater core via the blend door.  There is no way to clear any air flow blockage in the heater core area that I know of.

 

I am a bit confused because in an earlier post you answered a question about sufficient air flow from the vents.  Your answer:

 

On ‎12‎/‎2‎/‎2019 at 1:43 PM, int3man said:

Yes sir we have air just no heat.

 

Now you are saying "a little heat but no large movement of air"?

 

- John

[int3man]

Hi John,

               That is true, there is air movement but nothing like the A.C. Blowing on max. And MAX recirculates the air.  HMM I wonder how to get the MAX feature on while the heater is on.  I tried it with the Blend door moved over but it was cold air.  Defrost is moving air but not at the velocity of the MAX A.C.

 

Hope that is clearer.

Michael

[dripley]

put it on max and turn the temp to full hot. I have done that on mine and got hot air in the past. Not sure that will cure anything but you should get hot air. Max air does not control the temp just what the air circulates over or thru.

[int3man]

Well I did the same thing. I kicked the door to hot and turned the AC on MAX Blew Lots of Cool air.  That's why I am confused.

 

Thanks

Michael :- )

[dripley]

I will try mine in the am and see what it does. Have not tried the full max on hot in a long time. Tomorrow morning will present the opportunity.

[int3man]

Thank you sir you are a gentleman, in spite of the feathers!!  And please see how much air you get through the defroster?  Same as the face vents or about 1/3.  I get about 1/3.  Once I got the Air door to hot I was able to warm the windshield.

 

Michael :- )

[Tractorman]

You cannot get air from the defroster vents with the mode selector in the Max position.  The only way to get air from the defroster vents is to select Defrost or select the combination Floor / Defrost.  Max air selection will draw air from the cab via the recirculating door position and send that air through the panel vents.  The air temperature will be controlled by the blend door position.

 

You can, however, get any temperature of air (from very cold to hot) in any mode (Defrost, AC, Max , Floor, Vent) because that is the function of the blend door.  So, if you are getting a reasonable amount of airflow coming from the defrost vents, there really can be only two possible causes for airflow not being hot.  One, the coolant portion of the heater core is significantly restricted; or two, the blend door mechanism / ducting is faulty and cannot direct all of the airflow through the heater core.

 

 Hope this helps...

- John

[int3man]

HI John,

                Yea that confirms what I was thinking.  The blend door is full over so there is no flow through the heater core.  I'll work on flushing it tomorrow.  Any one know what the hose size is off hand?  I have to take the truck in to get the batteries tested tomorrow.

 

Thanks!

Michael