xxwildbillxx

Experiencing a low heat/no heat problem that began late last Winter... which I had hoped was just a fluke but w/Fall temps setting in, the problem doesn't appear to be a fluke. When I run the heater, I get about 30 seconds of warm-ish air, then the air begins to turn completely cool/cold. When I test ran the heater this past Summer, the heater blew hot air just fine and figured things were back to normal but now w/temps dipping into the 30's at night...the heater is back to blowing warmish air for 30 sec, then blowing nothing but cool/cold air thereafter...same exact symptoms as late last Winter! Anyone know if this is a "blend door" issue or (if I'm lucky)... maybe just a plugged heater core(?)

marathon

I had similar symptoms in my '05 plus a slight sweet odor of antifreeze. It was both blend door and clogged/leaking heater core. You can do the blend doors with the Heater Treater products without pulling the dash (see their website) but at the ages of our trucks you might as well pull it and do both at the same time. You won't end up doing it twice.

xxwildbillxx

I've seen the Heater Treater products/videos and the procedure looks relatively easily. First things first... think I'll borrow the pinhole flex inspection camera from work and poke around in the HVAC housing under the dash to dbl check the blend doors and heater core to see if it's leaking...I'm totally in denial on this being a blend door or leaking heater core and hoping it turns out to be something that's less of a PIA...

47Dodge

I had the opposite happen to my 2005. The truck would move to full on heat. It ended up being the HVAC control head. The head that fits in the dash with all your controls.


I had my recirc door fail and ordered the heater treater kit. It was a very straight process to redo the doors. I recommend them. After doing the doors all I had was heat. Fire up the truck and it would turn the servo motor to full on heat. Called heater treater and they said it could be the servo motor but highly unlikely as they don't usually go bad. In the kit there was a 9volt battery plug and wire set so you could plug in and turn your servos if needed to get the doors installed. I used this to move my blend door back to full on AC. Fire up the truck and had AC but after 30 seconds or so it moved the door to heat and would not move back to cool at all. Heater Treater was very nice to me and continued to talk to me about my problem even though it was not their doors causing the issue. They guy finally said you probably have a bad control head and it cannot calibrate your new blend door. I could still turn the fan on and off with all speeds. I could move all the various doors from vent to defrost just fine. I just had no HOT/COLD control. That **** was dead. At the time 3 Years ago there was a national back order on the control head for my 2005. It was months before I could get one from my parts store. The dealership had one for like 500$ or I could get it at my parts store for 130$ or so. What I did was extend the heater treater 9volt battery wire and simply plugged it into my blend door servo. If you reversed the battery you could turn the motor from hot to cool or back and forth depending on how you touched the 9volt to the connection. I had a wire with a 9volt connector on it hanging on the middle of my dash and kept a 9 volt battery right there so I could move the blend if needed. After like 6 months the back order was done and I got a control head and put it in and it calibrated and all was well after that.


47