Topic: thermostat for electric fan

[rwing1]

hey guys I tried my hand at building a website with my ISP.  Give a look at http://home.maine.rr.com/rwing1/JeepElecFan.html and let me know if it is any help.  Might be a bugger over a dial-up line with all the pics I put up!

[lanulos89]

[Guardian7]

Erik, the flex-a-lite kit has a mechanical sensing bulb which mounts through the fins on the upper part of the radiator just below were the hose dumps the hot coolant in. The relays for on/off/auto are built into the side of the shroud along with an adjustment for temperature settings. So when the coolant in the radiator goes above your setting, say 200 degrees then the fan kicks on. Therefore as long as there is airflow through the radiator to keep the coolant from going above your 200 degree temp setting the fan stays off. I hope this helps explain the design for you.

Mark

[Erik]

i tooally understand how that adjustable relay/thermoswitch works... and i urge everyone to stay far away from them as they are no where near as accurate and reliable as a good thermoswitch would be when installed in the cooling system.  a good place on the yj is at the intake manifold where the coolant line enters/exits/whatever.....  it's simple to do and total cost of fittings is about $6 at lowes in the plumbing dept.....


what i don't understand is how someone, don't remember who, said they had an automatic device that would turn their fan off while they were in motion.  that would be great since the wind from driving would be adequate to cool the radiator. the only time you need the fan is while sitting still and temps are at 195 or whatever temp tstat you have installed.....  the only way i could see this being fabricated would be to have a speed activated switch but with the mechanical speedo in our jeeps i didn't see how this was easily hooked up.

that's where my confusion came in....

[rwing1]

One advantage to having the thermoswitch mounted on or very near the radiator is that the radiator coolant rapidly changes temps up/down while the engine/block coolant stays very close to the thermostat temp.  By using a sensor on the radiator, when there is airflow cooling the radiator the fan isn't going to run much when moving along. I suspect placing a sensor closer to the engine will keep the temp reading higher and might not cycle the fan as often... I suppose if you could get a switch adjusted right it should cycle properly even at the outlet neck on the water-pump.... in theory.  Although the adjustable switches aren't considered as "reliable" or accurate(how do you rate accuracy of something adjustable?) as a preset non-adjustable type, they allow the user to "play" with the setting to get it just the way you want it. I personally feel any electric fan conversion should have a manual operation back-up......  if the temp gauge starts climbing too high flip it on!  I used one from Hayden/Imperial best link I could find was the pdf file listing them all, pg2 has switches..... I just used the cheapy one but I used relays with it.   Just my opinions.....  no right/wrong here if what ya got works for you!
http://www.haydenauto.com/pdf/imperial/electric-fans/electric-fans.pdf