One issue that is a common problem with the 2004 to 2008 F150's is the stock fan. It's air "pull" during periods of long idle conditions causes the A/C condensor to not have enough heat pulled from it. Ford switched to e-fans sometime in the later years, and this helped.

I went with a two speed e-fan conversion, and it helped. However, during the hot summers in Florida, if I idle for a long period of time, the A/C is not as cold as when I'm running down the highway at speed (at which point the stock clutch fan is not in use).

If you have a different aftermarket grille or lights that block airflow, this may be hampering the stock fans ability to draw air past the A/C condensor and radiator during long idle conditions.
Also, use the max air setting in the truck; it cools the cabin air rather then cooling outside air.

 

The Wife's Escape does as well, but sitting gridlocked in city traffic..maybe it's my frustration levels making me feel warmer haha
Either way, mine works at an acceptable range. Long idle times does seem to hamper it a hair, but while moving it's great.

 

The size of the cabin is also a factor. All f150s have the same ac system, but a single cab is much easier to cool than a crew cab.

 

Folks this only has to do with the system performance itself, nothing else. Those of us having issues, have systems that cycle between 44-48. Fords IDS computer indicates that the Evaporator coil is not cooling in the range of spec design, 36-38.


With this happening, we get vent temps from 44 on the low end to 54 on the high. Too wide of a cycle on and off!


This issue has nothing to do with size, windows or anything else. Go look at the long post called "cycling fix" where folks are using a "hack" to get their systems to cycle better and work.

 

I searched the 2004 to 2008 forum for "cycling fix" and found no matches. Did find this sticky though in the 2009 to 2014 forum:

https://www.f150forum.com/f38/compre...ng-fix-271852/

Not sure if it applies to our year trucks though; could not find an exact answer as to the location of this plug where a resister or photometer is installed. I's a very long thread. Posts in particular: post 22,23, to measure the resistance of the temp sensor used to control the compressor cycle "on/off". Post 30, from a master Ford tech recommends checking for dust buildup between the A/C condensor and radiator, and recommends only using the MAX position after cleaning, with this suggestion:
There's an idea, if you wanna mod your ac in a safe way, UNPLUG YOUR FRESHAIR ACTUATOR.

It talks about potentially higher pressures in the A/C system, and no one can say for sure the long term effects on the A/C system. If you live up north, the system could ice up in winter time, as your A/C still cycles on whenever you run the window defrost, even with the temp control on hot.

 

https://www.f150forum.com/f38/compre...ng-fix-271852/

 

As I have in my post....

Where is this plug located in the 2004 to 2008 Models that you install a resistor in? Is it behind the glove box door as the 2010 and up models?

 

Don't know or even if those year models have this type temp probe in the evaporator coil. My 08 ran a constant 40 degrees and I was told by an ac shop that I was very lucky, that they usually see these at 42-44 or higher vent temps.


Sorry