My AC unit in my new 01 Screw 5.4 doesn't seem to blow very cold until the rpms get up there. At idle it is cool to cold, but I have to leave it on max ac with max blower to keep the cabin comfortable. As soon as I jump on the freeway and hit 2K rpms for a couple of minutes, the AC will freeze human skin on contact. What gives? Is there a fix for this? A bigger pulley? A trip back to the dealer?

My 99 expy did not have this problem.

THanks,

Ken

 

Mine works fine you might want to check back with the dealer ?

 

Ken800,

My 2000 F150 xlt 4x4 s/c does the same thing,
The reason, (and by all means I am no expert in HVAC)
this is hapenning, is that your condenser needs to
be turning at X RPM before you get the coldness you desire,
Lets say that your driving with the AC on for a while, and you
stop at a red light for a while, you should be ok, as the condenser
has been condensing cold air for quite some time now.
However, if you just turned it on, It hasn't had enough time to
condense enough air to cool the cabin down, until you start driving
and bringing up the RPM's to condense more air.

This is about the only explanation that I have to this,
Mine does the same thing.

In fact mine makes a weird hissing noise behing the instrument
cluster when giving it gas while the AC has been on for a bit.
Dont know if I should bring it in for that neither,

At any rate, I wish you luck, and from what I understand,
This is considered normal.

Take care,

Morley

 

Don't ya miss the days of R-12 when you could freeze your blankety blanks off by the time you got to the end of your street?

R-134 requires higher pressures and isn't as efficient as the old R-12. What you're experiencing is quite normal for a hot truck.

When starting off in a truck that's been sitting in the sun for several hours, you need to get rid of the super heated air as quickly as possible, then you want to cool down the interior mass as quickly as possible. So, this is what I do:

1. Get in the truck and start the engine right away with A/C control at MAX A/C, fan on HI.

2. Lower all the windows to let the superheated air out.

3. Drive and keep track of the air coming out of the vents. As soon as the air feels cooler than the air blowing in the windows, close all the windows.

4. Leave it on MAX A/C until it gets cold, then turn the fan down. If it gets too cold, turn control to A/C to start bringing warm outside air into the system.


Basically, leave the a/c on MAX setting until the interior surfaces cool down. This will lessen the heat load on the a/c system when you open the vent when you turn the control to A/C. If you run the system on A/C too early, the a/c can't cope with cooling the inside mass AND the hot air being brought in from outside. The other thing about running it on MAX is you dehydrate the air a lot better which makes it feel cooler.

Remember, it's one thing to cool just the air, but it's quite another too cool all the mass that's found inside the truck. There's only so much BTUs the a/c can pump from one place to another and in hot areas, it's not enough to cool the interior air, mass, and incoming hot air at the same time.

btw, the compressor will kick off when you accelerate the truck so that will affect the cooling capacity momentarily.

 

Not only is it hotter than hell in a frying pan in Houston, but it's humid. The compressor is turning it's slowest at idle. Your Expy may have had a larger compressor due to it's increased interior capacity. If you feel that it performs poorly, you should at least have the dealer check it's function.