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Taurus fan power requirements

2K views 18 replies 10 participants last post by  YelloJeep 
#1 ·
I need a new fan clutch so I decided to go with a taurus fan instead. I have read everything there is to read on this install. Got the fan and mounted it in. Tight fit between it and the water pump pulley but it fits and the shroud width is just about perfect. So far so good.

Ready to wire it up now. Just about every write up on this mod talks about the massive power draw of this fan but the fan I got came with part of the wiring harness which has two inline fuses (one for each speed) which are only 40 amps, plus the wire going to the fan motor is only 10 gauge, at most. I have some heavy wire (6 and 8) laying around so I could use that but that seems like overkill for such a short run and a bending connecting headache. The distance from the fan to the relay is only about a foot so it seems like sticking with #10 wire should be fine. Or maybe #8 from the power source to the relay then #10 from there?

What is the general consensus on this part of the install? Many of the write ups seem to use fairly small wire but I used a couple of pieces of #16 just to test the fan and it got pretty hot pretty quick.

While we are talking about this; what is the consensus on a fan controller? There are tons out there but for some reason the ones that go into the radiator fins seem like a bad idea to me. For now I am just planning to get it working with a manual switch to see how it performs then thinking about drilling/tapping a temp switch into the thermostat housing; those switches only cost about $10. Centech makes a controller that works with the existing temp gauge sender but it is $79.


I have not taken any pix of this and there are probably plenty already but I will after it's done if anyone is interested.

Thanks
 
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#3 ·
I only run the high speed. I used 8 gauge stereo wire because I had a ton of it with a maxi fuse already built in. It's powered straight from the master battery switch (made my own body harness) through a $25 100 amp 100% duty cycle snow plow soleniod from Grainger. It's grounded straight to the battery with 10 gauge. The soleniod is grounded by my ECM but Painless makes thermostatic switches for about $12 you thread into a water jacket or thermo housing. I don't have a switch anywhere in the system, I let my computer do the thinking for me.

DO NOT use the radiator probes! I've never messed with the $$$ controllers but give it a shot if you like.
 
#4 ·
I have the radiator probe and have had it for a while with ZERO problems. Thats what was hooked up to my thermostatic fan control module.
 
#5 ·
Wow, two for and one against the "fin" sensor. I should have done a poll.

My thinking is that the temp of the various areas of the radiator will vary wildly, so placement would be important.

thanks for the feedback, so far.
 
#7 ·
1 ton yj said:
The fin type sensors are inacurate. Just because they work doesn't mean they work well. The thermostatic switches are cheap and so easy to install it does not make any sence to not use one.
Thats why I'm asking. I have not examined my engine completely to determine if there is a place to screw in a sensor other than the existing location where the gauge connects, and I would like to keep the gauge. Is there another plug somewhere.

Plus, riddle me this. If I get a switch on the engine somewhere that turns on at say 200 and off at 185, in theory it would never turn off because I have a 195 thermostat so the engine temp would never get lower than that.

That's why I was thinking to put it in the water outlet, after the thermostat. That way the enging would warm up to temp and eventually the thermostat would open and send hot water to the radiator. This would trigger the switch to turn the fan on.

I also considered drilling a hole in the radiator and brazing in a bung for a sensor there. Or, I wonder if I could screw one into the drain plug?

I saw a picture on another forum of a setup with the upper radiator hose cut and re-joined with a metal tube that had a sensor switch in it.

Lastly, I have been looking around since my original post and I can't find a sensor/switch for less than about $35

I'm sure I am over thinking this but as my dad always says, "If you don't have time to do it right then you sure as hell don't have time to do it over again."
 
#8 ·
1 ton yj said:
The fin type sensors are inacurate. Just because they work doesn't mean they work well. The thermostatic switches are cheap and so easy to install it does not make any sence to not use one.
My cheapo $17 Advance Auto "fin probe" thermostat is very accurate. I used a Fluke Heat probe to adjust it and test it. It comes on around 196 and in 13 seconds the temp was down to 144 to 142 when it shut down. Every time. Granted you have to use something to measure the temp to find out where to set it, but then it's perfect. Of course I set it up when it was about 50 outside. Now that it's 100, it takes a little longer to cool, maybe 35 seconds on low speed. But thats not the probes fault. Here's my schematic if you want it.

 
#10 ·
1 ton yj said:
Why do you cool all the way down to 142? Am I reading that correctly?
That is the temp that the Fluke probe went down to on the radiator, not the temp of the engine.
Oh and the engine temp guage never goes below 190.
 
#11 ·
the fuses already on the fan are probably slow blow fuses. the extreme draw you hear about with this fan is mainly only on start up where it can pull 100 amps + for a second or so. once it's moving it'll settle down to about 30-35 amps on high, which makes sense for the 40 amp fuse.
 
#13 ·
I am running a Taurus fan through a 30 amp blade fuse and a relay controlled by a temperature switch mounted in one of the heads on the motor. It has not blown the fuse yet. I have a DC Controls controller ordered so the fan won't have to run all the time in cooler weather.
 
#14 ·
Don-T said:
I am running a Taurus fan through a 30 amp blade fuse and a relay controlled by a temperature switch mounted in one of the heads on the motor. It has not blown the fuse yet. I have a DC Controls controller ordered so the fan won't have to run all the time in cooler weather.
What kind of switch do you have in the head and where did you mount it? I gave a quick look around the other day and did not see an extra hole or plug into the water jacket.

The more I think about this it seems to make the most sense to measure the water temp in the radiator because if the thermostat is working correctly it will be closed until 195, then when it opens and the radiator gets a rush of hot water the fan will come on.

thanks
 
#15 ·
jbolty said:
What kind of switch do you have in the head and where did you mount it? I gave a quick look around the other day and did not see an extra hole or plug into the water jacket.

The more I think about this it seems to make the most sense to measure the water temp in the radiator because if the thermostat is working correctly it will be closed until 195, then when it opens and the radiator gets a rush of hot water the fan will come on.

thanks
I guess you are running the 4.2 motor. I don't recall a port to install a temperature sensor it. I have a SBC so there is a spare plug in the passenger side head. I bought a switch from Summit Racing that is supposed to close at 200* and open at 185* if I remember correctly. My thermostat is a 195*.

I have an issue with my setup because either the temperature switch is opening early, or there is much difference in temperatures in the motor. The fan starts at about 190*, the thermostat open at 195* and the temperature stays at about 195* so the fan is always running. I ordered a DC Controls controller in the hopes that I can get it set to keep the motor between 195* and 200* with the fan running at a slower speed. I will be measuring the temperature in the fins near the inlet to the radiator so the fan will not start until the thermostat opens and I hope it will regulate the fan speed to keep it as noted above.
 
#16 ·
Don-T said:
I guess you are running the 4.2 motor. I don't recall a port to install a temperature sensor it. I have a SBC so there is a spare plug in the passenger side head. I bought a switch from Summit Racing that is supposed to close at 200* and open at 185* if I remember correctly. My thermostat is a 195*.

I have an issue with my setup because either the temperature switch is opening early, or there is much difference in temperatures in the motor. The fan starts at about 190*, the thermostat open at 195* and the temperature stays at about 195* so the fan is always running. I ordered a DC Controls controller in the hopes that I can get it set to keep the motor between 195* and 200* with the fan running at a slower speed. I will be measuring the temperature in the fins near the inlet to the radiator so the fan will not start until the thermostat opens and I hope it will regulate the fan speed to keep it as noted above.
Actually that makes sense. If the switch is set to 185 and the thermostat is set to 195 then the fan will never shut off. Probably would be better to have a switch that turns off at 195 and on at 200. One problem with that though is that they are not that exact, switches can vary by 5-10 degrees.

Having said all that it still comes back to what seems like the better option of measuring the radiator temp. I am seriously tempted to braze a bung in the radiator for a sensor there.

As I mentioned originally I am going to wire up with a manual switch for now and get a feel for how often the fan needs to come on before I do anything with a sensor. After that my plan is to use a thre position switch on-off-on. First position to auto operation, then off, then manual high speed.
 
#17 ·
I have the Hayden "fin" type probe. I don't know where I should put it. I have an aftermarket radiator and the fins seem too close together to shove the little Ziptie thing they sent with it through there. I have heard about people just JB welding it to the radiator. That might be a little permanent for me (don't want to have to buy a new radiator if there is a problem. I have also heard about people putting the probe inside the top radiator hose. I kind of like that one but am concerned about it leaking or the probe lead getting damaged. What methods have you guys all used? And how well have they worked?
 
#18 ·
I did all the current measurements and posted them a while back. If you are doing the Tarus fan I would go with the Hayden controller(Cheap but funtional) because it is capable of dealing with the slow speed current from the fan. Wire it uop as designed. The conroller does have a high side for the AC you can use it to control a higher current relay or in my case I used a solid state relay that is stiched. The inrush is very high in the high speed but the amount of air that fan can move is nothing short of incredible and overkill for 99% of what you do with your Jeep. My .02
 
#19 ·
I have the controller and it will be actuating a higher amp relay, I think I have all that under control. I just don't know the best way to attach the probe to the radiator or in the top hose. I would like to know how other people have mounted it. I like the idea of putting it in the top hose I'm just wanting to know if anyone has had any trouble with leaking or damaging the lead off the probe. Oh yeah, the controller has two terminals, that aren't labeled. does it matter? Or does anyone know which one should go to ground and which one should go to the relay?
 
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