ziggy

I've searched the forum and come up dry.... My 04 has extremely cold AC coming out of the drivers two vents, but the passenger two are barely cold until you come to a full stop, at which time they slowly cool down to the temp pushing out of the drivers' ones.

Any guesses?

04 Diesel

That is what mine does also.

Jeff in TD

Low on refrigerant charge is most likely cause.

Ram Daddy

Just had the same thing happen to mine...had it evacuated and recharged , and it`s better now , but I swear it`s still not as cold on the pass. side , but everyone that`s ever in that seat is always cold anyway

Jeff in TD

Yeah, the way the thing is set up, the air going through the side of the evaporator where the inlet is goes to the driver, and the air where the discharge is on the evaporator goes to the passenger.

If most of the liquid refrigerant has already vaporized before it gets to the other side of the evaporator...


P.S. In this system, hot coolant flows through the heater core full bore all the time, and temp is controlled by blend doors directing a portion of the air through or around the heater core.

AC cooling performance can be improved greatly by installing a valve in the heater line. Cost me like $12.

ziggy

i don't think it would be because it needs a charge (of course I could be wrong), but the cold air coming out of the drivers side is so cold it'll make you hurt, and still warm on the passenger. The blend door sounds a bit closer to my situation. Where could I find more out about this door?

Jeff in TD

This thread will be helpful.

https://www.dieseltruckresource.com/....html?t=210483

I'd check charge first, though, since it is simple and known to cause a temp difference between driver and passenger side.

If yours is extreme, you could very well be right, but pulling the HVAC down is an all day job that requires evacuation of the refrigerant anyway, so I would still check charge level first.

Jeff

ziggy

thx, i'll post an update

Buzz

Did you put a valve in the heater hose line so you can shut off the water going thru the heater? Does the heater hose coming out of the engine and going into the heater core serve any other puropse? Is there any adverse effects of the cooling system? Do you have a picture of your valve installation? thanks.

Jeff in TD

Yeah, I put a valve in the heater core line. Auto parts stores can provide you with a valve designed for that purpose. The heater line only runs through the heater core and back to the block. ISB engines are used in many applications where there is no cab heater, and it hasn't caused me any problems.

I've mainly noted a difference when it is up around 110 f, and I'm working the engine.

I posted a pic of the valve installation on the heater treater door thread.

https://www.dieseltruckresource.com/...s-t271212.html