We are having an issue with the front air not blowing cool all the time. Sometimes if we hit a bump or something its like something is jogged and it blows colder but the rear air always blows cold. Also the front air blows colder with the rear air on. I put gauges on it and I have the right amount of refridgerant in it. Any suggestions on what I can do.

 

Check the compressor connections near the dryer and compressor. That had happened on a few of our med units in the past. Usually the one you see here or the one up near the compressor that you see here.

The connection will unsnap, then you can twist off the male end of the connector from the lines. Very little refrigerant will be lost. Make sure when replacing that the connector blades look exactly alike.

 

Find this grey thin hose, make sure it's plugged in, if yes trace it to make sure it's intact. This is on the 6.0 however it's in the same area ( passenger side) of your V10.

 

Here it is, on the v-10 just to the left of the PVC hoses....

 

All my connections looked good. I did notice that there are 2 lines running towards the front that are rather oily and Im posting a pic of those. I may try to just change the expansion valve and do a pull down and recharge and see if that helps since nothing is really standing out. All the blend doors appear to be working and the vents blow in the correct areas when changed. Dont know if the oily lines are a problem or not, could be a leak but every time I put the guages on it it shows to be full, well not maxed out but in the range and it doesnt seem to go down any.

 

I know this is an old thread, but I am having the same symptoms with my Excursion. A/C is working in front, but not so good. Rear A/C is great. Front is a little cooler when the rear system is turned on.

Did you ever resolve this issue?

I would be a hero if I could make this work a little better.

Thanks, everybody!

 

Repeating myself in different threads but had the same thing occur. Had assumed it was the front expansion orifice but wound up being a combination of sticking damper doors and a clogged expansion core. Clogged in that it was so dirty that air was barely getting through. When in front A/C only the pressure sensors would keep tripping the system off and so it was short cycling and cooling was poor. When the rear A/C was on not only was the rear cool but with the increased refrigerant flow the system would not short cycle and so the front A/C was significantly cooler. To compound the problem the air damper doors in the front would stick and when driving would divert air over the heater core. Solutions in my case was to clean the expansion core and to cycle the system though all of the mode (all the different air vents, heating and cooling, fresh air and recirculated).

 

Thanks for your reply. That sounds like good information. When you say "clogged expansion core" , do you mean that the outside of the evaporator (and it's cooling fins) were full of debris? Or that the inside was clogged and impeding refrigerant flow?

I also thought about replacing the expansion orifice, but I'm not sure how hard it will be to get to it, and I don't know how likely it is to be an issue. Many posts suggest that it could be low on refrigerant, or contaminated with air. My plan today is to pull a vacuum on the whole system and recharge it.

Does the entire dash have to come out to get to that evaporator (like it did on my Chevy)? What a pain that was!

 

Having the same issue too. Have any pictures of this repair?

Thanks

 

Outside/fins full of dirt and so limited air flow.

 

OK, so I pulled a vacuum on the system and pumped in 5 -12oz cans of freon. The sticker says that the capacity of the system is 4lbs4oz (68oz or 5-1/3 12oz cans!). Previously, I had only 2 cans of freon and lines full of air.

Anyway, this was a great improvement, and I am calling it "good enough", but I don't think it performs quite up to standards of what I would expect for a brand new car. I would like to inspect the evaporator, but I am afraid of what it might take to get to it. I don't have a manual covering this, and my 1995 GMC was a nightmare (the whole dash had to come out). So, I'm in no hurry to dive into that, unless someone can tell me it will be easier.

I don't have a vent thermometer, but it was 97 degrees in Illinois yesterday, and after a few minutes running, it was reasonable comfortable.

By the way, I did hook up the "max AC" vacuum line, blocking coolant to the heater. The line had been hooked up to the side of the valve, doing nothing. I moved it over to the end of the plunger on the valve, and presto, it worked. This made an instant improvement, not only for the A/C, but also for the fresh air vent.