[joshdice13]

2011 ram 3500 6.7l duel climate control. HEATER NOT HOT I flushed heater core, blend doors work, coolant full, trucks at 180 degrees. as soon as I turn heater on, after truck has warmed up it blows hot air for 3 sec then cools off. I just started noticing if I run the temperature down then up a bunch of times it will get a little warmer but nowhere near where it should to be. anyone have a climate control module go out? that seems to be the only thing left before I spend a bunch of $$$$ I would love a little feed back

 

[Smiley3303]

I am curious too. Mine needed up being as simple as a new heater core. Now I get heat much earlier and can use climate control. I went with an FVP core and did it by splitting apart the box rather than messing with the refrigerant and all that. It is a bit time consuming but worth it. There are a lot of connections and bolts to pull out the dash and the box. Part was like $70 on Rockauto and since I did it myself labor was just my time.

 

[drhodes73]

Having the same issues been fighting with this for 2 years now. 2013 2500 6.7. Have tried everything, without replacing the core. Might be my next step just don't want to pay a dealer.

 

[chuckb27295]

Following.

Minimal heat after warming up. Quoted $2500 to replace heater core. Haynes is in the mail.

2017 3500 6.7 Cummins, Crew Cab, Long Box, 4x4, SRW, Dual Climate Control.

 

[drhodes73]

Have you tried flushing the core. I'm going to give this one my try this time with some CLR. The last time was only with water.

 

[Corey_lax]

I flushed my heater core with a hose and got it flowing nicely. Still no heat. I always thought I had an airlock in the antifreeze but I finally pulled the plastic cover piece off the top of the radiator and found that it was leaking slowly allowing air into the system. I would have never noticed the leak because it was so small that there was never a puddle on the ground. It was not even really enough of a leak to notice the antifreeze level going down drastically, but enough to let air into the system. So one more flush of the heater core, and replacement of the radiator, and now I have 145 degrees coming out the vents.

 

[drhodes73]

Thanks for posting this, now I'm going to check the radiator.

 

[b.lee]

For the trucks with dual climate control,
Are there 2 blend doors?

OR just the one behind the glove box?

I'm trying to fix the heat in my 2012 2500 w/ dual climate control.
The heat will be fine for a month, then one day out of the blue it'll be cold.
It's been happening for the last couple winters now...

 

[5.7 Hemi]

I think there’s one behind the hvac box (firewall side).