It turns out they are different. 1999-2001 trucks engage the compressor in floor/defrost, where 2002-2003 do not.

 

" I'm not sure if the pre-2002 trucks have different selections or not."
FWIW both my old 74' F-100 and 88' Bronco used the A/C to dry the air. Neither of them worke on their last leggs and the de-frost setting was was a "fog setting". Kind of like my old 50' Chevy, need to keep a bag of tobacco on the shift **** to clean the inside of the windshield.

 

My family enjoys the truck but only likes to ride in it from fall to spring. The A/C is nowhere near what my wife's Jeep puts out (actual C-O-L-D air) so if we aren't camping or need to haul/tow something, it's parked unless I'm running an errand solo. I had the A/C system serviced a couple of years ago and it made a huge difference it but still doesn't hold a candle to most anything else. It cools the cab and keeps my head from sweating but does absolutely nothing for my back on a hot day...

I think standing in the shade with a slight breeze is about 258% more effective than my A/C system.

 

have you done the ac mod at all to your truck? Mine actually will freez people out if I let it....

 

As Jaime said, install a shutoff valve in-line in the hot water feed to the heater core from the block. Does not matter which one, it is just a loop from the block. It will stop the flow either way.

 

Even without the A/C mod, Stinky flat makes me back off the setting after about 20 minutes of driving - even when it's 108 outside.

 

Yes I have. Mine came with a valve to begin with but removed it and added the "Ranger valve". The first one leaked when activated so unhooked it (years ago) and finally replaced it recently when I replaced my radiator. As long as I'm not in direct sunlight and it's less than 80F it will eventually get cold but anything higher than that and it's only a cooling dehumidifier. The service done on it a few years ago made the biggest difference (low on pressure and refrigerant) and it was night and day with performance once everything was topped off and set correctly.

The condenser looked pretty good when I had everything out (radiator, intercooler, trans cooler). I used some compressed air to make sure there weren't any bug parts stuck in the fins and used a comb (Radiator Fin Straightener) to straighten out the fins as best I could (man those suckers are thin).

At 14 years old I'm sure there's some ailment that will require repair or replacement in the future but after the Buck$zooka (credited to TUGLY) I fired 3 times in the last year I'll live with what I've got until something fails.

My wife is losing her affection for the truck since over the last year it has seen the most down time in 9 years of ownership (3 months) and an investment comparable to the GNP of Palau to get it back on the road.

I will, however, say that the truck ran and made it home (and to the shop) every time I've had an issue. I've never needed a tow. I love this truck!