I have a 2002 fx4, 5.4 liter and I just installed two pro comp 14" fans, but I'm overheating. What should I do? I really like the horsepower change, but I don't seem to be cooling enough...

 

Have the same truck with a Flex-a-Lite duel fan kit.
First check to make sure your fans are running before the truck over heats, also check that they are turning in the correct direction.
Don't know if your fan unit has the similar type control module as the Flex-a-lite, however it has an adjustment you can manually set what temp the fans turn on and whatever they use to monitor the coolant temp my be in the wrong position or not working.
Had a problem of our truck over heating when the fans wouldn't run at very high outside temps. Turned out I had mounted the control module to high up in the engine compartment exposing it to the high underhood temps that would shut it down. Moving it lower eliminated this problem.
Also email or call the manufacturer for help in trouble shooting...

 

Definitely make sure it is blowing the right way, should have the fans installed on the engine side of the radiator and they should be pulling the air through from the front. Made this mistake on my GMQ years ago, did Ok at highway speeds but as soon as I slowed it would overheat since the fans were fighting the incoming air. All it takes is the wires being wired backwards. Driving over about 40mph you shouldn't need the fans on at all to keep it cool.

 

The reason is the Pro Comp 14" fans are way too weak for your truck. Thats what happens when you buy cheap fans and don't do enough homework to make sure you got the right parts for the job. Those fans only move 1800 cfm in open air, that figure drops a lot when you put a radiator in front of them. Thats just not enough for your truck.

What you need is to do it right, this will take care of you.

Flex-a-lite 270 - Flex-a-lite Monster Direct Fit Electric Fans - Overview - SummitRacing.com

This steps you up from the lame 3600 cfm without proper airflow shrouds to 5500 cfm with the proper shrouds. Yes it costs more, but these work. So lets lay out your options so you can make the best decision.

1. Your current fans don't cut it. Even if they had the shrouds, the CFM is just too low. They are out. If you continue to try to run these, you are gonna blow a head gasket at some point.

2. You could go back to stock. This would be the least expensive at this point, but you would loose all the benefits of going with an efan in the first place.

3. Buy the proper Flex-A-Lite kit and enjoy. Over time you can enjoy fuel savings, depending on the amount and type of driving you do. I run efans on my work van. There are fuel savings, the engine warms up faster (great in the winter), there is more power, and the engine compartment becomes a little less cluttered. The belt is much easier to replace when you don't have to route it around a mechanical fan.

Again, here is the link http://www.summitracing.com/parts/FLX-270/