the cooling fan runs continually loud even at high RPMs?

2001 FORD EXPEDITION
243,000 MILES • 5.4L • V8 • 4WD • AUTOMATIC
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JAMESRVANYA
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When driving with the A/C on the cooling fan runs continually loud even at high RPMs. Turn the A/C off and the cooling fan works as it should. I replaced the radiator thermostat water pump lower radiator hose and coolant reservoir. The fan clutch is only about 6 months old the above reason is why I changed the fan clutch. A/C doesn't cool really well unless the truck is idling. A/C compressor was replaced about a years ago new dryer accum the whole works. Thank you for your help in advance. I am really stumped with this.
Jul 23, 2021 at 5:32 PM
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ASEMASTER6371
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Good evening,

Can you give me the high and low side freon pressure readings while the engine is at 1,500 RPMs? I want to be sure the system is working correctly. You can rent a set of gauges at a parts store for this test.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

I want to get the A/C working correctly before the cooling system.

https://www.2carpros.com/articles/how-an-engine-thermostat-works

https://www.2carpros.com/articles/replace-thermostat

Roy
Jul 23, 2021 at 6:10 PM
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JAMESRVANYA
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Okay, I'll have to go get the gauges I don't have them I'll rent them. What should the Low and High pressure be?
Jul 23, 2021 at 6:14 PM
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ASEMASTER6371
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Depends on the outside temperature. Give me the readings and the outside temperature.

Roy
Jul 23, 2021 at 9:23 PM
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JAMESRVANYA
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I did get the gauges I will get the reading in the morning. Thank you
Jul 23, 2021 at 9:29 PM
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ASEMASTER6371
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Sounds like a plan.

Roy
Jul 23, 2021 at 9:31 PM
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JAMESRVANYA
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I went out this morning ambient 80F attached 77 PSI Low and 80 PSI High numbers are cold vehicle. Started vehicle ac on High MAX cold at idle 30 PSI Low and 255 PSI High. I increased idle to 1,500 RPMs constant 33 PSI Low and 300 PSI High. *FYI I have a shim that I use to keep the 1,500 RPMs idle so I can be at the front of the truck The fan comes in and the low side goes to 25 PSI and the compressor cycles pressure on the high side comes down to about 150 PSI. It appears to me that the High side pressure switch is not working. I don't know what the High side switch activates at. Would please give that information and this could be the problem. Maybe I'm off base. Please your experience will help me a lot.

Thank you,

James R Vanya
Jul 24, 2021 at 7:22 AM
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ASEMASTER6371
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Okay, when the fan comes on, the pressure comes down to the correct pressure. The high side should be 2 times ambient temperature plus 15%. 25 when the fan comes on is good. It is a little low.

Both pressures are a little low. Do you have cold air coming out the vents?

The high side switch opens and turns off the compressor when the high side pressure exceeds 375 pounds.

Roy
Jul 24, 2021 at 7:28 AM
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JAMESRVANYA
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Not really it gets about 66 or so idling driving it's about 70. Could the condenser be partially clogged causing the fan to engage more than it should? I have never had this fan run while driving down the road as it does now and the fan clutch is about a year old. my truck does not run hot at all. perfect temperature no matter how hot it is outside.
Jul 24, 2021 at 8:14 AM
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JAMESRVANYA
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could low R134a cause the fan to run more?
Jul 24, 2021 at 8:15 AM
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JAMESRVANYA
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I bought the fan clutch at AutoZone. Could the activation temperature be wrong on this fan clutch? I am going to check on a Motorcraft fan clutch.
Jul 24, 2021 at 8:20 AM
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ASEMASTER6371
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To be honest, I think you are low in Freon. When the pressures come down, they are lower than they should be.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

The fan is doing fine. No need to worry about that.

Roy
Jul 24, 2021 at 9:00 AM
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JAMESRVANYA
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FYI, I just returned from a trip to the bank about 8 miles one way I have a thermometer in the vent it read 70F driving. when I was in line at the bank it went up to 74F on the way back It lowered to 62F. that's as cold as it will get. How much should I add what should the pressures be at 1500 when it working correctly? Should the compressor cycle on and off it the system is working correctly?
Thank you,

James
Jul 24, 2021 at 9:47 AM
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JAMESRVANYA
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Thank you for the great link I'm reading it now.
Jul 24, 2021 at 9:53 AM
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ASEMASTER6371
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You need to recover what is in there first. You cannot tell the Freon level by pressure.

Evacuate the system for 45 minutes and then add the exact amount required.

Fluid Types
A/C Refrigerant .................... R-134a Refrigerant YN-19
Capacities
Capacity

Without Auxiliary Climate Control .................... 1.05 kg (37 oz)

With Auxiliary Climate Control .................... 1.78 kg (62 oz)

Roy
Jul 24, 2021 at 10:08 AM
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ASEMASTER6371
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Did you respond? I got an email but nothing came through.

Roy
Jul 24, 2021 at 12:19 PM
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ASEMASTER6371
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Still nothing, sorry.

Roy
Jul 24, 2021 at 1:04 PM
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JAMESRVANYA
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Okay, I replied using my Galaxy S20 and I guess you can't use a mobile device. Let's see if this works. I am going to take my truck and have the ac service as you suggested and when done I will update you with the results. I appreciate all of your help. Thank you James R Vanya
Jul 24, 2021 at 1:31 PM
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JAMESRVANYA
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FYI,when i replied with my cell and clicked the reply button the screen went blank and no message was above it like it is now replying from my laptop. Thanks again, James R Vanya
Jul 24, 2021 at 1:33 PM
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JAMESRVANYA
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I figure the 62 oz calculates to 3.875 can at 16 oz per can. My truck does have rear A/C so it's the 62 oz application.
Jul 24, 2021 at 1:35 PM
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JAMESRVANYA
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It will be Monday before I can have it serviced. Have a Great Weekend!!!
Jul 24, 2021 at 1:36 PM
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ASEMASTER6371
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The cans are 12 ounces, not 16 ounces.

Roy
Jul 24, 2021 at 2:14 PM