This is one of the reasons Ford went with electric cooling fans instead of the clutch fan. At idle, the clutch fan isn't pulling enough air through the condenser to remove the heat and reduce system pressure. The clutch is not engaged most of the time so it's spinning freely not with engine speed. The fan clutch will only engage when the air coming through the radiator is hot enough to open the thermal spring to engage the clutch. When the coolant gets hot enough the fan clutch engages and spins at engine speed. You'll hear the tell tale roar when you start to accelerate. This is probably why it blows cooler sometimes but not most of the time. There is no connection between the fan clutch and the A/C. If radiator temps are running normal the clutch won't engage to help the A/C.

On the newer F-150's, the electric fans on high speed pull the same amount of air as an engaged clutch fan but at idle. They will usually run on low speed but when the pressure in the A/C gets high enough the PCM will switch to high speed.

The Super Duties still use a engine driven clutch fan but those are electronically controlled by the PCM. The PCM can engage the clutch as needed when A/C pressure gets high even if the coolant temperature is normal or even cold, just like electric fans.

 

My 08 5.4 does not use a thermal clutch. It uses an electrical clutch engaged by the ECU. I think all 04-08 5.4s used this setup. Not sure about the 4.6s.

 

Nope, my 5.4 uses a thermal clutch (its a 2006). At least I think so. I don't see any wires going to it, and I've never seen any wires going to the clutch on any 5.4 serviced by FordTechMakuloco on his channel. Though, my fan clutch does randomly engage on startup for a couple minutes, but never while I'm driving (or when it gets really hot).

 

Not sure when they made the switch to the electrical/ECU clutch. Maybe it was an 08 thing?

 

My '07 & my '08 both have electrical fan clutches.

 

OK, based on what I see on Online Ford Parts Catalog for the fitment guide, it was up until 2006 that had a thermal fan clutch.

For visual reference:
-- Up to 2006
-- 2007 & 2008, until Ford used electric fans

 

Makes sense. For what it's worth, my local dealership tech tells me that the failure rate on those electronic clutches is very, very low

 

Yep the 05/06 is a thermal clutch and the 07/08 is an electric clutch.

Has anyone attempted a swap out? I don't think I would get much improvement as i would still be limited by the low RPM of the engine.

I am going to upgrade to 16 inch flex-a-lite fans (I did 2 12" amazon brand ones) to see if i can get more coverage and more airflow through the condenser. Although I am wondering if the clutch fan wont be able to move all the air that i am pushing through.

Also, a new shop by me had a window tint special on their ceramic tint and i got the truck done for $100. This seems to help a lot once the truck has cooled. I also got a HeatShield windshield shade which is a lot better than the crappy one i had before.

I am still trying to make out where the orifice tube is. Does anyone have a pic of where it is located? I cant tell from the other images. Is it before the accumulator or after it? Is it around the high pressure port?

I still need to cover my pipes with the insulation. Would it also be beneficial to throw some aluminum tape on there to reflect more heat?

I guess i was hoping someone found the silver bullet. Other vehicles use similar setups and will freeze you out in no time.

 

Hi
I forgot to mention earlier I have no problem stopped with my AC it only slightly warms but is still cold. It wasn't great untill I wrapped the line in styrofoam.
The orifice tube or expansion valve is in the line I wrapped in styrofoam where it connects to the condenser. I believe ford moved the expansion valve back on the evaporator on newer models.
Mine is thermo old style fan clutch. Make sure the spring in the center is not plugged with debris as this is what engages the fan when spring heats up it twist the center to make the fan spin faster.

 

I'll add this: for me, I can't see the benefit of replacing my current setup with electric fans. Even here in Florida, my truck does pretty well for going on 11 years of never having any a/c service completed. For me, the factory setup is good enough. YMMV