Electric Radiator Fan ... info to upgrade....
 

The basics first: I have a 1999 Grand Cherokee Laredo, 4.0L 6, auto ...

There is both the engine driven fan, and a factory electric fan. That electric fan was bypassed with a relay and switch when I purchased the jeep, and I have since returned it to a stock configuration - the original fan relay was bad, and after replacing that and restoring the wiring, it all works as intended.

However ... particularly in the summer, the temps run hotter than I'm really happy with...technically not overheating, but higher than I'm happy about. If I get into heavy city traffic, or decide to tow something with any weight to it, I can get into trouble quickly.

What I'd like to do is upgrade the electric fan to something that would move more air, but allow me to retain the factory control system.

I know the fan is fused at 40 amps, so I need the draw to be below that, but I'd like to know what the factory fan is actually rated to draw, and what sort of cfm the fan is capable of moving.

I've asked two different dealers these questions, and was rewarded by a collection of dumb looks ...

Anyone know the answers, or where I might find them?

an electric fan that moves more air will also draw more amps. you could replace the mechanical fan with an aftermarket direct drive fan. summet racing should have them. it will pull more air but your mileage will go down.

Here is something you COULD do, although it a bit far out! Drill 2 small holes in your fan clutch opposite each other, use air pressure and blow out any fluid in it. Then fill it with epoxy resin. My brother did this on a Chevell instead of replacing it with a solid spacer. That 6-bladed fan made quite a roar when he was done. It DID effect his gas mileage though.

Adding an aux trans cooler will help if you don't have one. Since you have both fans, I'm assuming you already do. My 2000 only has the electric one, but my A/C doesn't work so it stays below 220* in the worst conditions.

There is a whole detailed write up on how to replace the stock clutch fan on the 4.0 . It will cool the engine with or without the electric fan. http://www.jeepforum.com/forum/f310/...-swap-3917042/