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AC blowing cool but not cold. New compressor, condenser, accumulator, and orifice tube. Ambient air temp = 75, low p =40, high p = 165, vent temp front and rear 57 at idle.
the other day was 94 and the vent temp was 73. Not nearly cold enough to make it comfortable in the cab. I am at a loss here, don't know what else could cause the problem.
Today it was 81 degrees. It took 8 miles for the air to get somewhat cool. I have owned 4 Excursions and I have never had one that had effective AC in very hot weather. If you look at a chart for the X, at the outside temp(75) should have Low side pressure of 35-45... psi. The high side should be around 150 to 170 psi so your pressures are spot on. I wonder if something might be going on with the vacuum switch for the heater hoses feeding the heater core...I'm just guessing at things but if the switch does not close completely, you would have heat being transfered into the heater core which is not what you want. Sometimes the switch can go bad or commonly the vacuum hose comes loose. The hose is the gray one on the passenger side which attaches to a larger round diaphram connected to the switch. The nipple on the diaphragm is very short and it can be hard to get it on to where it will stay on. Like I say, just guessing on an idea as I am definitely not an AC expert.
So I do have a vacuum leak, which I traced to the heater control valve, so that is being replaced. However that wouldn't have an effect on the regular AC settings. The temps and pressures stated were with the dial on regular AC. Even still 73 degree air when 93 is just sad, my 2002 jeep does much better. Would love to know what people who live in the south are getting . If I lived in Georgia I would have to sell this thing because it would be unbearable. Seeing these are all over the south and people love them, they must be getting better numbers. The hot and cold blend doors are controlled electronically, I did have the thought that they may not be closing fully but both front and rear would have to have failed. My only other thought is that to much oil is in the system. It calls for 14 ounces. Assuming that is what I had before I replaced parts I added 3 ounces with the new compressor and an additional 2 ounces over what came out of the accumulator, so now I might have 19 ounces. In addition I replaced the condenser which reduces the total refrigerant required from about 4.2lb to 3.24lb. So now the system has 25% less refrigerant with potentially 35% more oil assuming that the new condenser doesn't change the required oil amounts.
Why would you put an undersized condenser into a vehicle that already has its refrigeration system maxed out even with the correct sized unit? That's a recipe for very poor cooling performance. Add that to having too much oil and less refrigerant and you're going to be steamed.
Start over. Evacuate the system, drain and flush out all the old oil, install the properly sized condenser, put the correct amount of oil into the system as prescribed by the service documentation. Evacuate and recharge to specification.
@projectSHO89 The condenser is not undersized, it is a Ford motocraft condenser designed for the excursion and superduty. Ford revised the condenser to have much thinner refrigerant passageways and as such it doesn't need as much refrigerant. It came with a sticker with the revised refrigerant amount. I did replace the oil per the FSM.
Why would you put an undersized condenser into a vehicle that already has its refrigeration system maxed out even with the correct sized unit? That's a recipe for very poor cooling performance. Add that to having too much oil and less refrigerant and you're going to be steamed.
Start over. Evacuate the system, drain and flush out all the old oil, install the properly sized condenser, put the correct amount of oil into the system as prescribed by the service documentation. Evacuate and recharge to specification.
I agree 100%! My Excursion when properly flilled, cools as good as anything else I've owned. Something isn't right, evacuate the system, drain the oil, pull a vacuum, inject the right amount of oil and recharge the system. It should blow cold!!
@projectSHO89 The condenser is not undersized, it is a Ford motocraft condenser designed for the excursion and superduty. Ford revised the condenser to have much thinner refrigerant passageways and as such it doesn't need as much refrigerant. It came with a sticker with the revised refrigerant amount. I did replace the oil per the FSM.
Then you should have stated all of that up front. We ain't psychic...
Owned since new. AC is excellent in South Florida heat and humidity.
It works so well that position 2 on the blowers keeps the truck cold in the Florida summer heat! I always keep both the front and back air on.
Keep at it and report back with your results. But in general, the AC is excellent. What I like most, compared to most vehicles, is the large volume of air the system moves on lower fan settings.
Very cool and no need to have the fan blasting with all the fan noise.
Just my opinion but I am an AC freak after baking in the Fl heat for over 30 years!
AC blowing cool but not cold. New compressor, condenser, accumulator, and orifice tube. Ambient air temp = 75, low p =40, high p = 165, vent temp front and rear 57 at idle.
the other day was 94 and the vent temp was 73. Not nearly cold enough to make it comfortable in the cab. I am at a loss here, don't know what else could cause the problem.
Any suggestions?
Did you pull a vacuum, and with a micron gauge to see the actual progress, and did you inspect the inlet face of the front evaporator for dust and blockage?
How much debris was on the original orifice tube, did you replace with the correct OE rated orifice tube?
@projectSHO89 Where are you getting the corresponding temperature? @MARCSPSD Thanks, that is what I was suspecting. Mine was in Florida for 10+ years and I believe the AC worked well at that time @01__Excursion I do not know if a micron gage was used. I made the repairs and had a shop pull a vacuum and charge the system. Office tube had minimal debris and was replaced with a stock OEM one (https://www.rockauto.com/en/moreinfo...t=6936&jsn=470). I replaced the components because the old compressor had a leak at the shaft seal. @Nicmike Replaced with the correct orifice tube.
I did get the Max AC fixed and it is a little better. At 93 ambient temp I can get about 60 out of the vent on Max AC which is better but still not good enough. Driving gets about 55.
