We've just returned from a 2 week vacation pulling an RV in our 2008 F450. During the first week we crossed the Mojave dessert, and about roasted because the A/C barely put out any cool. So we dropped the truck off at the Ford dealer where the 'fixed' the A/C, indicating there was a couple leaks.

The A/C definitely blows cold now, but not very much. Coming home across west Texas, we were still quite uncomfortable in the cabin. The A/C was blowing, but not enough to really cool the cabin down.

My wife drives a 2007 Honda Civic, and the air comes out of those vents quite strongly. For example, you can hold you hand about 3-4 feet away and feel the cool air. On the 'repaired' truck you can barely feel the cool air 1-2 feet. It also doesn't sound like it's blowing nearly as hard.

Is this just the way the 2008 Ford F450 A/C is designed?

 

-Do you have all (4?) of your fan speeds? Starting at the lowest speed, can you hear the motor speed up as you turn up the speed control?
-Does the truck use a cabin filter? If so, and it's plugged, that will restrict your airflow from the vents

If it's neither one of those, you likely have an evaporator thats plugged externally with dirt, dust, organic matter, etc. All of the air that goes through the air handler flows through that damp, tightly finned evaporator first. Not sure about your 450, but on many vehicles the instrument panel has to be removed to access the evaporator.

 

Thanks for the tips. Yes, the fan speeds all work, And the A/C blows cool when it is cool outside. I'm wondering now if the recirculate gate is working. I can't feel any difference when recirculate is on or off.

 

Even if the recirc door was stuck in the fresh air position, you should have good airflow.
Listen for a change in the sound of the blower when switching between AC and MAX AC. If it changes at all, it's likely working as it should.
The interior air intake (recirculated air intake) is usually visible above the passenger foot well and you can often see the recirc door through the grille. You may be able to actually see the movement.

 

You have a blend door issue the one in question is directly behind the glovebox on the plenum.

 

The Blend Door is the one that directs air through the heater core (or around it). How can that be the issue?
He "might" have a Recirculation Door issue.

 

Does it blow harder when it is in regular then when it is in Max ac? Mine did and i found a plastic bag sucked up in the inlet by the passengers foot well. It works great now that the circle k bag is gone.

 

Mine will blow very hard and very cold but won't switch from the defrost vents to A/C vents. Any suggestions?

 

Read the HVAC FAQs...

 

Vacuum leak.

 

Found that the "box" sitting next to the vacuum pump had a dime sized hole in it from something and apparently contributed to the vacuum pump burning up. Replaced both, good and cool.

 

FYI - there was a 2nd ac line leaking. So even after the dealer fixed it, after a short while it was not blowing cool again. So another trip to the dealer, another $750, and now the ac is cooling ok.

 

hey everyone! i am trying to figure out why my ac blows at every speed but not hard. I just replaced the whole system: (evaporator, clutch, condenser, and the accumulator)... i have no idea what else to try.

 

Why were those parts replaced and who did that job? Were they experienced or just winging it? Was the re-assembled system properly evacuated, leak tested and charged to its proper refrigerant level?

 

What about the blower motor itself? If it's old it could be weak and not spinning at it full RPMs.