Since I have a Horton on my truck, and I may be one of the owners whom John mentioned about having a problem with it, I'd like to say a few things.
I think the Horton fan clutch and an exhaust brake (I recommend the BD) are the two best accessories you can add to these trucks.
For those of you who are not familiar with the name, Horton makes fan clutches for over-the-road trucks, and they are very high quality, heavy duty items that are made to last. They're standard equipment on all big rigs. People often have the mistaken notion that it is an electric fan, which it is not. The fan clutch is electrically activated, similar to the clutch on your air conditioning compressor, but the fan is still powered by the engine rotation, not by an electric motor. The Dodge OEM fan has a viscous coupling that thickens when it gets hot, causing the fan to engage, whereas the Horton has a sensor that monitors the coolant temperature and another one that monitors the pressure in the air conditioning system. The fan is completely freewheeling when it is not engaged, so it doesn't consume horsepower.
When you buy the Horton fan clutch, you get a replacement fan along with it. This fan has more blades than the factory fan, and when it comes on, it moves some serious air! An added benefit to having an electrically acitivated fan clutch is that you get a switch on the dash that allows you to turn on the fan anytime you want to. I do that when pulling into a parking lot or gas station after a long drive, to help draw off heat and lower the temperature under the hood before I shut the engine off.
In normal driving conditions, the fan will almost never come on. Why? Because you don't need it. I used to live in the Los Angeles area, and even on hot summer days with the air conditioning on, the fan would only engage when I was sitting at a red light. Even then, it would only engage for a few seconds at a time and then shut off. That was all that was necessary to reduce the pressure in the a/c system. Sometimes it would be on as I would take off from a red light, but then the ram air effect would take over, and the fan would shut off before I was up to maybe 10 mph.
There have only been a few times that the fan came on because of high coolant temperatures, and those times were all in 100+F degree temperatures on mountain passes in the summer. I remember going to Bakersfield in late July for a funeral. I insisted that my folks and I use my truck instead of their car to make the trip. Those of you familiar with the infamous "Grapevine" mountain pass on I-5 know there are big yellow signs saying "WARNING - to avoid overheating, turn of air conditioning for the next (xx) miles" (I don't remember the number). In the summer, you will always see broken down cars on this grade, with their hoods up and steam pouring out. But there we were, flying along at 70mph, with the a/c on full blast, as comfortable as we could be in our dressy clothes. The outside temperature read in the 100's for the entire trip, once as high as 114F in Bakersfield!
I mentioned that I did have a problem, allow me to explain. One of the fan blades contacted a bracket that runs down the back of the radiator. This bracket holds the wiring harness. One of the fan blades bent completely backwards and looked like a taco shell. I had to buy a replacement fan, and when I went to install it, I discovered the reason why the blade hit the bracket. The two upper radiator bolts were loose, and I could rock the radiator back and forth. I had an accident last summer, and the truck was in the body shop for front end work. I have a feeling they forgot to tighten the upper radiator bolts. So, anyway, that problem was no fault of the Horton clutch or fan.
I hope this doesn't read like a commercial, but I'm very happy with this product and highly recommend it, especially if you tow something. BTW, I should mention my truck is a 5-speed, so I don't have a transmission cooler.
Andy
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