Heat on one side of vent-warm on the other side- Blend door?

[jr70895]

2013 Ram 1500 5.7, recently had shop change the water pump and thermostat. When I run the heater the passenger side vent gets to 145 degrees, driver side 105 degrees. Did a bleed on new water pump so no air lock. To be honest the vents might have been this way for awhile as in my area the heater isn't used too often.
Not sure how many blend door actuators this truck has but was told 5 and the dash needs to be removed in order to replace them. I did a google search and seen one is right behind the glove compartment. It's easy to get to and was told by a shade tree mechanic this is the only one that would need to be changed.
Removing the dash looks like a real pain and not sure I wish to tackle that adventure.
Thanks for any input.

 

[mtofell]

Classic case of a clogged heater core. Fairly easy to flush yourself with a few basic tools and skills. Lot of recent threads on here with specifics.

 

[BurtShaver]

X2 in the heater core

 

[5150Eddie]

Yep my 2016 was the same way. Cold one side, warm on the other. I was convinced it was the blend door but when I had an issue with the manifold bolts I took it to my local garage (never the dealer) I talked with him and he said those trucks are notorious for having clogged heater cores so he flushed mine out and all is well.

 

[Dusty]

It could be a Mode Door issue. There's a way to calibrate the Climate Control system and synchronize the Mode/Blend doors. Perhaps someone else remembers the process.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 145008 miles.

 

[JmGuTe]

Honestly its your heater core. This is classic Dodge/Ram/Chrysler. The heater core gets clogged due to poor cooling system maintenance and casting debris that clogs it over time. Wifes old 200s suffered from it and my Ram 2013 had the same clog. You have two options look up southmain auto on youtube and search heater core flush. I did this on both cars and it solves the issue for a brief amount of time. Ultimately if it issues comes back you'll have to yank the dash and replace the heater core. I did it on the Ram and it solved the problem of little to no heat at first, however, I flushed it soo good I removed the debris that was keeping the coolant in LOL. It developed a leak and had to replace it. At that time, I just replaced both the radiator and heater core along with flush the block again to avoid any more debris from potentially clogging the system.

 

[Flip-er]

i was having same thing on my 2013 big hirn with hemi
after 2 years I bit the bullet and had the heater core changed and since they had dash apart I had the vap coil and solinoid behind dash changed too, NOW the heat eill run you out of truck.
You can flush the core BUT that will only last so long.
I was getting very hot air on passenger side and cold to luke warm if I was lucky on drivers side

 

[mtofell]

I was getting very hot air on passenger side and cold to luke warm if I was lucky on drivers side

Part of me was almost disappointed when I fixed it since the cooler air on the driver's side was a poor man's dual climate zone and often appreciated. Wife is always cold!

For OP - Here's documentation of my experience:

Low Coolant = Low Cabin Heat?

So, my coolant level was down 2-3 quarts due to the radiator drain valve rattling loose/slightly open (at least I hope that's it - but another topic). I initially noticed the heat output being bad - lukewarm at best, then, the same day, noticed a small puddle of coolant under the front/driver...

www.ramforum.com

Post #6 is the heart of it and has the tools/parts I used to flush the core.