I just moved to Tx and am using the AC a lot more than in recent years.
the AC freon (r112?) got replinished in 2008 I believe. Now when I try to engage the rear AC unit in the passenger area, it just blows warm-hot air. The front panel vents seem to be working fine. What advice can anyone give?
Secondly, there is a "whining" sound coming under the hood, I believe it is non-related to the AC. sounded like low power steering fluid at first. Topped that off and checked oil and trans, but still hear the sound. The van only has @95K miles and has been very good so far.

I appreciate the help and look forward to hearing your experiences.

 

The system should have R-134a freon in it. Why was the system "REPLENISHED"? Was it due to a component failure? If it was for a compressor failure, the system probably wasn't properly flushed along with the proper components being replaced after such failure. Sound like the rear expansion valve is either plugged or failed in the closed position. More information can be provided with further information about your A/C systems history.

 

The replinish occured because it was not cooling at all. I believe it was a condensor that had to be replaced at that time under warranty about 20K miles ago.

It's probably worth noting, although I've only had if for 5 years, I'm not the original owner....I bought it "used" from a dealer.

for the rear line being stuck closed or blocked, do you mean the r134 line to that rear A/C system? Air blows out the vents, cycling at desired speeds by using the control panel, it's just not blowing cold.

Thanks

 

OK...Here's some rambling...

The Freestar with dual A/C uses a split system. The high pressure line splits at the fire wall. At the split, one line goes up to the front evaporator and uses a fixed metered orifice and the other line at the split goes down under the van to the rear evaportator and uses an expansion valve to meter the flow of refrigerant. The expansion valve could be plugged with debris or freezing due to moisture in the system. Since water is heavier than the refrigerant, and the rear feed line is lowere than the front line, moisture in the system will normally flow back to the rear exopansion valve and freeze there while leaving the front unit working properly. Did the dealer replace the Accumulator/Dryer when the system was repaired? They should have and they should know that it should always be replaced anytime an A/C system is opened for any type if repair or looses it's charge due to a leak. The accumulator/dryer has a type XH-7 desiccant in it to absorb moisture in the system. However, it can only absorb a certain amount. After the desiccant has reached its absorbsion point, it cannot remove any more moisture from the system. At this point, you have moisture flowing thru the system that can freeze the metered opening closed at the expansion valve. The excess moisture will then combine with the refrigerant to form hydrochloric acid which is extremely corrosive to metal components. This corrosion will flake off and flow thru the system and can plug the expansion valve and also trash your compressor in time.

If you look under the van on the driver's side, directly under where the door latch is you will see 4 lines. Three large and one small. The first 2 outside lines are the coolant lines to and from the rear heater core. The next large is the low pressure A/C return line from the rear evaporator and the fourth small line is the A/C high pressure line to the rear evaporator. The heater core lines will always be hot as coolant flows thru the system at all times. You have a heater control valve that diverts the coolant back to the engine block or thu the rear heater core. With the rear A/C ON and running, the small high pressure line should be hot to the touch and the large low pressure line should be cold to the touch. If this is the case, the expansion valve is operating and then I would suspect a bad heater control valve.


If your heater control valve is failing or failed, the heater control valve will not shut off the flow of water to your heater core. Thus, even in A/C cold mode you will get heat out of the upper A/C vents.

 

Wow! You really know A/Cs! I'll check out those lines.

thanks

 

What can I say...I "LIKE" A/C. There's nothing like a comfy ride to make any trip easier. Update your findings and if you still have problems, we'll go from there.

 

Just recently my ac started displaying an issue. While running the ac in just the front it doesn't seem to get very cold. As soon as I turn the rear ac system on it blows cold, and the front also starts blowing very cold. As soon as I turn the rear ac off the front stops blowing cold. It is not blowing hot air out of the front just not cold. Any information regarding this issue would be greatly appreciated. Thanks everyone.

 

i have exactly same issue, is your problem solved?
or can someone help me please, thanks