Intermittent AC - blend air door?

[Rhondasway]

My folks' '04 is having intermittent problems with the AC. It will work fine then suddenly go warm and stay that way, not fun for them travelling in 100 degree desert heat. Is this the blend air door, and if so how does one fix it? I saw an older thread on 3rd Gen's from '04 but am not sure they're the same.
Alternately, what will Dodge do to fix this? I really don't want to get neck-deep in this truck, have to take the dash out, etc...
Thanks for any help.

 

[Kry226]

I would have the system checked out first. Sounds like it might be freezing up. There was a TSB many moons ago calling for moving the fin sensor due to freeze up issues, but that does involve removing the dash.

 

[Rhondasway]

I would have the system checked out first. Sounds like it might be freezing up. There was a TSB many moons ago calling for moving the fin sensor due to freeze up issues, but that does involve removing the dash.

Thanks! Is there a way to look up TSB's? And does that mean they fix it for free? (we love us some free)

 

[Tuesdak]

I suggest a local AC shop that can look over the system for leaks and evac and recharge the system for you. This only costs double what a off the shelf guess the charge R134a can kit costs. Your system could be low on freon causing the freeze up and the only way to properly service the system is leak check then evacuate and charge the system by weight.

Are the passenger side vents warmer than driver side vent temps indicating a low freon condition?

Other problems like a bad cooling fan kicking out the AC high pressure limit switch, compressor clutch coil, etc. can all cause the AC to suddenly quit.

Not sure if it applied to 2004's. Here is the sensor location memo (not a TSB and not free out of warranty) info:
Replace the evaporator temperature sensor with part number 5140727AA

https://www.turbodieselregister.com/threads/168202-AC-Fin-Sensor-Relocation-WHERE

 

[Rhondasway]

I suggest a local AC shop that can look over the system for leaks and evac and recharge the system for you. This only costs double what a off the shelf guess the charge R134a can kit costs. Your system could be low on freon causing the freeze up and the only way to properly service the system is leak check then evacuate and charge the system by weight.

Are the passenger side vents warmer than driver side vent temps indicating a low freon condition?

Other problems like a bad cooling fan kicking out the AC high pressure limit switch, compressor clutch coil, etc. can all cause the AC to suddenly quit.

Not sure if it applied to 2004's. Here is the sensor location memo (not a TSB and not free out of warranty) info:
Replace the evaporator temperature sensor with part number 5140727AA

https://www.turbodieselregister.com/threads/168202-AC-Fin-Sensor-Relocation-WHERE

Great info, thanks! Probably will end up at Dodge since we're such a small town, but at least we're educated.

 

[Crunch]

Here's a site that lists TSB's for various vehicles:

2004 Dodge Ram 2500 TSBs

Unfortunately, most dealers only fix TSB's for free when the vehicle is under warranty. But if there is additional work to be done they might do the TSB at the same time for free.

 

[Crunch]

I suggest a local AC shop that can look over the system for leaks and evac and recharge the system for you. This only costs double what a off the shelf guess the charge R134a can kit costs.

I agree that's the best solution, with one caveat: In Texas they aren't allowed to recharge a leaking system. So if you take it in and they evacuate the system and find a leak they won't recharge it until it's fixed. You either shell out the bucks to fix it right then, or live without AC. In my case, I have a very slow leak somewhere that bleeds out about one can of R134a every 18 months or so. I could take the truck in and have it checked out, but that could end up costing me several hundred $$$ instead of the $15 every three years. Yes, I'm taking a chance by simply recharging it myself, but I charge to the low end of the range to keep head pressures low and the AC has worked fine for several years. I also have a mode door that is giving me trouble, so my long term plan is to wait until the air bag recall stuff settles down and when I take my truck in to have that done I'll have the mode door fixed, and let the slow leak shake out however it is going to shake out. Given the slow nature of the leak I'm hoping it's just a loose connection or O-ring that isn't sealing.

 

[Tuesdak]

Likely a slow leak on these trucks is the evaporator. It has taken several 'sniffer' tests to finally find it on mine by getting a hit on the AC drain. So yeah adding a HVAC rebuild to the air bag recall sounds like a good plan if the dealer will play nice with it. Mopar dealer wholesale and HeaterTreater doors are like $700 for parts alone. (Online Mopar parts sales are cheaper than the dealer. Doors, heater core, and AC evaporator.) Due to the evaporator being common I say adding dye to find a leak is a waste (and I prefer and have an electronic sniffer myself).