I have a 2003 Ram 25 Cummins Diesel. I've had it for 9 years and this is the second time this has happened. For some weird reason, the air on the driver's side blows cold but the air on the passenger side is significantly warmer.

I took it to a shop the first time and the guy figured it out stating something about filling the coolant and/or it's "weird" how you have to do it. My stepdad has a 2005 or 2006 and it's happened to him too.

My question(s) is has anyone else had this happen and is it owner fixable? Any ideas are welcome. I'm not an idiot with mechanics but I'm not going to rebuild a motor either.

 

Sounds like it's low on freon. Do you have dual zone climate control? If so, you may have an issue with one of the temp doors. Otherwise, low freon. You can buy a can and refill it every year or two, but I'd wager you've got a leak and you should probably get it fixed.

 

i just fixed my dodge carvan it was doing the same thing i went and bought a blend door actuator which my has three of them i had to firgure out which one wasnt working and i change it and it works now

 

Low refrigerant. Dad's 02 1500 did the same thing.

 

it is a blend door issue. 3rd gens are notorious for having blend door issues.

my old mans common rail he used to have with the dual climate control did the same thing.

ice cold for the drivers side, blowing hot air on the passenger side. passenger side blend door was broken and blew heat while the drivers side blew a/c even though both controls were on A/C.

dodge really should have done a recall on that because it is a HUGE problem that effects ALL 3rd gens.

definitely not a low refrigerant thing.

 

Then please explain why I fixed my dad's truck by adding refrigerant? lol HOT and "warmer" are two different things. What the OP was stating is EXACTLY what I had go wrong on my dad's truck. Added a can of 134a and it was good.

 

low refrigerant would make air warm from both sides of the truck...

02 2500 and 3500 is still second gen with second gen single hvac controls.

he can certainly check his refrigerant pressures, but overcharging the system will cause more harm than good if it is not low...

 

You missed the part where I said 2002 1500 not 2500. lol It's a 3rd gen. And I'm saying that THAT is what fixed the problem. I've looked it up, on DF and numerous guys had the same problem and it was all fixed by adding refrigerant. I would think a blend door issue would make it to where you were getting hot air all the time no matter what your a/c system was doing.

 

there is more than one blend door. driver and passenger side have their own controls.

passenger can have heat on while driver has ac on...or the other way around, etc...

all done via blend doors. when they go bad which they often do in 3rd gens, it causes that issue.

 

No offense, but do you work on A/C systems?

The way the freon flows through the evaporator isn't even - if the refrigerant is low it can flow through just the top or bottom. The airflow through the evaporator isn't just one big path evenly mixed, the left and right sides are split off, causing the temp difference. I've seen it happen, and fixed it before.

YES, Chrysler had a big issue with blend doors, but low r134a can also cause the problem. The easy way to tell is to go full hot and see if the temp is still luke warm on the one side. The fact that it was fixed the first time by adding freon just reinforces what I'm saying.



OP, you may have a blend door issue if you have dual zone climate control, but my money is on there being a slow leak somewhere. Compressor shaft seal, o-ring, or even a tiny pinhole in the condenser or evaporator.

If you haven't had dye added to your AC, I'd recommend going to your local auto parts store and getting a can of dye that you just hook to the low pressure side and squirt for a few seconds. If you have a uv/black light, grab some yellow safety/shooting glasses and the light and see if you can find where it's leaking.