When my heater it on cold air blows out of the drivers side vents (upper and lower) and hot air from the passenger ones. What would cause this? Do you think that there is a blockage somewhere or maybe a control baffle or someting? With the cold arriving, I probably shoulf fix this...lol.

 

Welcome to the wonderful world of a broken blend door. The dash will need to be removed to fix it.

 

check out www.heatertreater.net they fully explain and show the problem with a few videos. depending on how many control doors are broken it will cost between $130 - $200 for their parts. But that is way better than a shop or dealer fees to fix, they will remove the dash completely (hopefully your dash isn't cracked to **** and needs replacing too). A few members on here reported very good results from them and they are on my wishlist now.

 

Thanks for the link. I watched the videos and when I have the time I definitely wll attempt this. One thing though, what I did notice was that there is a temp difference when I turn the heat on and off. When it is cold (below 40) the air still remains cold. But the other day it was about 60 out and the air felt hot. I didnt compare to the pass side, but it was nticeable hotter than in the morning. Could this be the core or is it still most likely the blend door?

 

There could be both problems. What year is your truck and when was the last time the coolant was flushed and changed? Next time you're out driving and the truck gets up to operating temp, feel the upper radiator hose, and both small hoses that connect into the heater core. All three hoses should be around the same temp. If one of the heater core hoses is much cooler than the other one there's probably a blockage.

 

I have a 2003 1500 and heat only works on passenger side. From what I gather, it's my blend door(s) or the actuators for them. How do you know which is it? I am aiming for the cheapest fix possible even if that includes similar factory replacement part(s).

 

Boxerguy84, check out the link I posted a few posts up. All of our trucks use the exact same airbox internals. Those of us without the dual climate control have both blend doors linked together at the factory. When you watch the videos that they have posted you will realize that it's very likely the DC motor actuators are still good, it's the weak, plastic gear axle that breaks. The only way to know for sure is to take a few panels of the dash off, they show you how and it's not nearly as bad as taking the entire dash apart.

 

Hello, thanks for your tip. What's dual climate control exactly? I'm considering the heater treater door upgrade.

 

Dual climate is when you have two ***** or levers on dash one controls drivers side temprature the other is passenger. If you have only 3 dials one for speed, temp,and vent selectiob then you have a single,

 

So I realize i never updated this, I took caseys-dodge's suggestion of feeling the heater hoses and it was clear that one was hotter than the other. I also noticed that the heat was sort of working, it just depended on outside temps. I flushed out the heater core really well. The whole process took about 20 mins, and now I have heat! Thanks guys. Ill do a complete flush over the summer just to clean it all out.

What had gotten me all confused was the issue if it was the blend door. I thought it was until i realized that the heater temps varied with the outside temps. If it were the blend door, i would never get warm air out of the drivers side vents.