Our Excursion is an 01 V10 2WD. The front a/c started to not blow as cold as the rear air. I bought some refrigerant to add to it but on the way home we hit a bump in the road and it started blowing cold. My wife said that some days its cold and some days not so but the rear is always cold. My gauges show that its not low low but its not to full either, could probably hold a can but dont think it would hold more. Is there a switch or something that is maybe shorting out that is causing it to not blow cold sometimes. Thanks in advance.

 

Check the blend door operation.

 

I just did the AC on my Ex last night (did a full purge + recharge), and I can tell you that when I had as little as two cans in the system, the rear was blowing ice cold, but the front was luke warm. When I got into the fourth and fifth cans the front started blowing colder and colder until it was blowing cold air everywhere with a full charge.

Point being - perhaps the behavior on a low charge is that the front looses "power" first, so maybe you're seeing symptoms of a low charge.

 

Sounds like a leak somewhere.

 

Funny I have the same issue, rear blowing colder than the front. I charged the system with about half of a big can and the little pressure gauge attached to the can and hose showed the right pressure (according to the can and the outside temp). The AC blows colder but not all the time. I noted a small bubbling/hissing from the high pressure valve (I had to take the cap off to hear it). I think that valve is slowly leaking on mine. I have not emptied the system yet to try a rebuild on that valve.

I do know from experience that if an AC system is not full, you'll hit pockets of "air" without much refrigerant while the AC runs and the effect is cold sometimes, not cold other times.

 

I put a can in today but its not really colder. It seems to blow good and cold going down the road but in slower in town and idling it doesnt blow near as cold. I washed the radiator and condensor (in front) about 6 months ago and they still look clean. Havent done anything around the heater core area.

 

Make sure your fan clutch is in good shape. With the engine hot but off, can you freely spin the fan? Do you get the roar on a hot day down in Texas? What are the hi and lo side readings at idle, on max, low fan, and on high fan?

 

Good chance your valve to shut the heater core flow is bad.

 

Hooked the guages up to it and checked static pressure with engine and all off (first photo) and then at 1500rpm idle with all on max air per manuals procedure (2nd pic). Air was blowing fine today, read 40 on the low side and 250 on the high side. No distinguishable difference between front and rear.