I have am 04 Dodge Cummins and I'm trying to figure or why it blows hot on passenger side and cold on driver side can anyone help me out

 

Welcome to the site. There are literally a ton of these same type threads posts here on the site. It is because of a failed blend door. Try doing a search for those keywords

 

I know I'm considered a Newb on this site, and this is my first post on here, however I'm on #4 Dodge 3500 trucks Cummins.

Here is why the passenger side is blowing hot and driver is not if the blend door has been replaced, or at least this is my experience with it.

If you read up on the older TSB's that Dodge put out, there is one regarding the same issue, and it's happened to me personally.

The TSB says that if the AC coolant charge is low, and when the charge is low, the passenger side will blow warmer than the driver side. I know you think I'm nuts and don't have a clue what I'm talking about. However, I live in Phoenix AZ and I know all about this issue. At first I did not believe it, but also in the TSB's there is a bulletin about the factory Dodge freon hoses seep freon over time as the lines are defective and should be replaced.

So what did I do, I brought my rig down to my mechanic and have him evac the system and measure the Freon out of the system, and damn sure, the Freon level was low, recharged the system to the factory spec Freon levels and started it up and guess what the passenger side was blowing as cold as the drivers side.

So now what do I do, every year before the summer season is upon us in Phoenix, I bring my truck to the mechanic and have him evac and measure the system and recharge, and every year, there is a loss of Freon from the system. I have had the system completely gone over, and there are no leaks at any of the connections and everything is tight, even under the dash when I did the blend door.

I bet that if you bring you system to the mechanic have him evac check the amount, it will be less that what recommended on the sticker under the hood, and once recharged the passenger side will blow cold.

Give it a try. If I had access to a complete TSB Bulletins, I would find the TBS's with the details.

Good luck
Rob

 

mine does the same thing its the heater core.look it up on youtube 02 dodge ram heater core guy shows how to do it looks like a big pain even the guy at the shop i take my truck to doesnt want to fix it i got to do something winters coming.my heat only comes out passenger side and my ac only works on my drivers side and my de fogger doesnt work at all.do you smell coolant coming out the vents at all?posted the vid for you from youtube.

 

ok the op is an old post from 2010 grrrr.

 

I am also having that same problem. But I notice when I turn off my blower and leave the selector **** on hot then turn on the blower it blowes hot for a min or two then gets cold again so I'm thinking a flush may help my situation.

 

 

I kept thinking there is no way its the heater core to why its cold air on the drivers side and hot for the passenger.. . I tried all the actuators I made sure all the doors worked and finally after realizing everything works.. I figured what do I have to lose.. Im from the old school where a heater box is just a box.. Now with this duel climate stuff.. Im starting all over.

So i went and cut the lines on my 2011 dodge ram and flushed the heater core out.. After i ran the water in then out of both lines I poured some CLR into the core.. After a hour I flushed it all again. Re did the antifreeze. Burped the system and TADA i have heat.. I say sorry to all the guys who were adamant with this fix.. Some of old dogs can learn new tricks..lol Hopefully this works for a while..If not I will be replacing the heater core in the summer while its nice out...

Thank you everyone for the guidance.