I'll drop my $.02 in...

As mentioned, you need the shroud.

Also, if you're changing t-stat, I HIGHLY advise going with Motorcraft t-stat. It's only a couple bucks more and it's OEM, 192°F.
If you're opting for a lower degree t-stat, then buy a Mishimoto 180°F.
Both are high quality and are known to perform for years. Anything from the parts store is junk. And Stant is junk.

The same goes for the radiator cap. I only replace with Motorcraft. Stant is junk!

Always check the t-stat by boiling it in water and make sure it opens and closes.

Stay away from Junk Fail-Safe t-stat's.

I may be preaching OEM Motorcraft for the cooling system, but I always do and the same goes for ignition.

These two systems work the best when using quality Motorcraft parts.

I dealt with enough of those problems on many Ford trucks and it always comes down to quality or quantity.
You can either fix it Right now or the Right WAY.

 

There is 95% of your problem. I would not bother with taking out the thermostat. Get a fan shroud before replacing anything else.

They were designed for a reason. No fan shroud is like taking the tires off the rims then going for a drive then complaining the ride is rough and there is a lot of noise. Not to mention it drives terrible in the rain.

 

If the truck runs cool while moving, chances are it may be the fan clutch as suggested. Once the truck is moving, the fan does not do a whole lot of help. Lack of a shroud is not helping cool the truck. This reply is cooling 101, only. Just some of the basics.

 

If you do just replace the fan clutch without going electric conversion, remember that there are several different types of fan clutches. Some are normal no AC, some are for trucks with AC (move more air sooner) and some are even rated heavy duty which I can only assume means they lock up really fast to move air practically all the time. Might not be a bad idea for Florida?


Also, don't put Chinese junk on there since it is such a critical part if you can afford not to, although more and more Motorcraft parts I buy seem to be made there sooo... SHM

 

Don't fret, I have learned over the years that just because something is made in China doesn't mean it's junk. China can actually make some good stuff. It's all about the company providing the specs and the level of quality control said company desires for the finished product.

For example, I had a 29 gallon air compressor from Harbor Freight. Pump, motor, tank all made in China. Would you believe it was the quietest and smoothest running twin cylinder single stage I have ever heard? The motor was Chinese, the pump appeared to be an IMC (or was it a clone?), but there was no casting flash, no appreciable amount of metal shavings in the oil after the initial break-in, none of the crap you normally see with China garbage. It ran great til I sold it for a 60 gallon two stage.

Motorcraft I'm sure has stringent QC standards for their parts and they wouldn't allow bottom of the barrel, run of the mill China garbage to be sold with their name on it. So just cause it's made in China don't mean it's automatically garbage. It's only as good or bad as the company that awards the contract to the Chinese factory allows it to be.

Now, all that being said: I still prefer to BUY AMERICAN when possible!

To the OP: I'm in Florida too. Get a fan shroud on that thing and install a 180 degree thermostat. As mentioned before, stay away from the "fail-safe" thermostats! I've run 180 degree 'stats for years. Go with Motorcraft brand, anything from the parts store is a crapshoot! You'll still have plenty of heat for the mild winter we have here, but your engine and cooling system components will thank you during the summer!

 

MERCA!!


I'm with ya man, still going to keep buying the Motorcraft, quality is quality.

 

I am fighting the same problem on my 92, it has a new fan clutch good shroud etc. what I have found researching is that Ford discontinued the fan clutches which is bad because the aftermarket only makes standard duty clutches not the heavy duty an ac equipped vehicle uses.Ford offered an even heavier duty clutch from the normal ac clutch for conversion to r134a because of the extra air flow needed,however these are only available apparently on ebay if you are lucky enough to find one.
My solution is either going to be full electric fan or helper electric fan haven't decided for sure yet. For now I just turn the ac off if im stuck idling in a drive thru. (update advanced my timing some and has seemed to help )