Thanks for the feedback guys.
Blaine, since the lead to the switch is tapped into the blue wire, the fan can / will only operate when the key is in the "Run" position, regardless of switch position. When the switch is off, it will not run at all. I had it wired up manually (I just had the wires going through the hood and the driver door) for a little bit just so I could driver her around, had to take another trip to Napa. Just from that I decided I would probably forget to turn it on or off right away so I spent the extra 20 minutes to wire it this way, I think it was the better choice.
Now I don't have to worry about it.
Woody, they are about $18 a fan here, a $1 to get in the yard, maybe $25 of wire, relays connectors, and switches.
Grease, yup that is the Ford Starter Motor relay, plenty of beef to take on the initial draw, I've run it on high to make sure it works, but it works perfect on low... but it is still winter here
ZJ, I did not use a temp switch, but you can easily. Ilya gave me a sweet diagram of wiring a fan with an adjustable temperature switch, but that just wasn't in the cards for now. As far as before and after, well I have only driven for maybe 60 miles and it was around 38* out, most of it was on the highway. The real test will be slow crawling over the rocks in MOAB this summer. Just on low speed and testing it in the garage, it cools it off very quickly.
Phil, swaping out your radiator will be a perfect time to do this! I talked with Ilya through PM's and he have me some info on wiring it with a temp switch and such.
Ryan, yep, the 5.9's use an e-fan as well. As far as power increase, that would be tough to say. I just did a full tune up, I fixed the leaking plenum gasket (which lowers performance) , and I hadn't driven anything larger than a 4.0 XJ for two weeks. Sure she seemed to be more perky and responsive than normal, but I can't honestly tell you that was from the fan. Another benifit is that the fan had great cooling ability at slow speeds. Think wheeling here; your creeping over obsticals all day, sometimes giving some good pedal and letting off as soon as you make it over/through. The mechanical clutch fan operates off the belt speed. When going slow you are not moving that fan very fast nor moving much air through the radiator. True you can rev the engine to get the fan speed up and cool down a little, the e-fan just does it easier and constant... and you can turn it off if you want for water or anyother reason. Even with my crappy stock alternator, low does not suck it too much. High on the other hand gives it a hard time at idle.