taurus install

So I've got most everything I need to install a taurus fan when I re-read the article about it on go-jeep.com. He used the AC fan for the power to his taurus fan. The AC fan comes on around 215* if I'm not mistaken. Anyone what to help me through the thought process of why use the existing AC fan wiring vs. using a variable temperature fan switch?

I just read the '00 FSM (Factory Service Manual). The aux electric fan will turn on at different temperatures for a 2.5 vs 4.0 and there are different variables for each engine. (The first reason you shouldn't hook up your Taurus fan to the aux/ac fan)

The normal operating temperature for Jeeps is 210*. The aux fan automatically turns on well above 210*. The new electric fan should turn on before it reaches the normal operating temp because it's harder to cool down the engine when it goes above 210*/215*. Plus, you don't want to risk over-heating and breaking something. (The second reason you should hook up the electric fan to come on with the aux fan)

I hooked up my Taurus fan so that it runs when the engine is running. However, the ideal setup would to have a switch turn it on at 195*
or 200* or so. With a switch, the engine will warm up quicker too.

Also, I routed the belt line like go-jeep suggested and could never get enough tension on the a/c pulley. It squealed every time I turned on the a/c. I also tried many different configurations and belt sizes. There just needs to be more belt wrap on the a/c.

Give yourself plenty of time and have a back up plan just in case you don't get it done before you need to drive you XJ.

E

um.. how about buy a $4 relay, use a power source that is hot only when the key is on from the relay box on the pass fenderwell, and call it good.

I've already got a variable thermal switch and had planned on it kicking on around 200* on low, like you said so it's easier to keep at the normal operating temp. I don't want the fan to just be on at all times, so I'm going to wire in a switch to control when it's on high and so I can turn it off for water crossings or whatnot. I figured using the AC fan wiring would be a bad idea, just wanted a couple reasons why. Appreciate it.

You should not have the fan coming on before the themostat setting but after it. Otherwise it will be running all the time! You loose most of the benefit of running the electric fan in the first place as now you are just loading up the alternator more rather than having the drag for the mechnical fan. I have run twin electric fans off the A/C circuit for about 8 years now and dont have any cooling problems what so ever. It works perfectly and have never been anywhere near the red with the Taurus fan setup as my site has.

I understand your point, but when the AC fan kicks on my gauge, inaccurate or not, is already around 220*, if the fan kicks on then my coolant temp is always going to be bouncing from 210-225ish, then correct? but if the fan kicks on right before the thermostat opens up the coolant going into the engine will be cooler, and keep engine temps closer to 210-215ish. Correct me if I'm wrong, I'm relatively new to all this.

It is working perfectly the way you have it now. A lot of people get worried about the temperature it runs at on a stock XJ and think it is too high. But they are designeed to run that hot and you will get better mpg and less wear from doing so. The fan is meant not to come on until 220 and switch off above the thermostat ( 195 ) at 200.

Gojeep said:

It is working perfectly the way you have it now. A lot of people get worried about the temperature it runs at on a stock XJ and think it is too high. But they are designeed to run that hot and you will get better mpg and less wear from doing so. The fan is meant not to come on until 220 and switch off above the thermostat ( 195 ) at 200.

Click to expand...

How hot are you taking about??

They are designed to run at 210* (their normal operating temperature) Right?


whitneyj - You are on the right track. Having the fan come on at 200* will help your Jeep warm up quicker and will help maintain the normal operating temperature. The auxiliary fan is an "auxiliary fan." It's meant to help cool down the engine when the main fan can't keep up.

I do not see any reason why you should be running your Jeep above 210* (The normal operating temp). If it always ran at 215* and you never had a problem with it, then I'll say that 215* is probably ok for your rig.

E

I'm going to try and get the schemtic on here to show everyone. I'm no electrical engineer by any means and had a buddy write it up for me, we're both looking for a little constructive critisism on this. Give me your thoughts once it's on here.

http://thumb18.webshots.net/t/63/663/9/26/55/2773926550084738078dVgpBs_th.jpg
here's the schematic, I've read all the articles I can find about this and the general concensus is nothing smaller than a 40 amp relay, some guys are running 85 amp continueus duty relays, which I think is a little overkill. Shoot me some thoughts.

Your fan will cool a lot more then just the rad and AC condenser. It moves air inside the engine comparment at idle and slow speeds. Cooling the engines outside and the engine compartment in general is more inportant than many think. Your computer is up there, as well as extending belt life and many other parts, It CAN help keep the cabin cooler
(IMO) It's much better to have it kick in well before 220 or whaterver E-fan kicks in at.
How about using your variable thermal to kick in the low speed of the Taurus fan at 160-180. This should permit a good quick warnup in the winter. But not let under hood temp skyrocket in the summer.
Then tap into the stock E-fan to run high speed side of the Taurus fan.
This set up will give you the right air at the right time. Keep the load on the charging system at min. By only using high when needed.

A good bud is hard to find.
Even harder to lose.
Work safe.

That's exactly how the schematic is wrote up. The variable thermal switch will control the low and when the pcm tells the AC/aux e-fan to kick on, it'll open the low speed circuit and so only power goes to the high speed. However, I think 160-180 is pretty low for the fan to kick on at, I'm going to start at 200 and see where that takes me. I'm waiting for my welder to come in, ordered it last week, so I can get started on my cowl induction hood. My underhood temps are ridiculous and am hoping the hood will take care of that.

hopefully this picture is better
[/URL][/IMG]

anyone have any thoughts on this?

whitneyj said:

anyone have any thoughts on this?

Click to expand...

Seems like it would work. This is one I came up a while back to do the same thing.

I came up with this one that uses only two relays and a three-way switch. I am only going to use the low for auto-on, and have the High wired for straight manual only for low speed wheeling or what not when the temps start to rise. The middle position on the switch would disable both for water crossings.

I was thinking about doing what you did BB1980, but I like the idea of not having to worry about anything but turning it on and off. Dave4107 I'm going to run your schematic past the guy that pretty much drew up mine and see what he thinks. I'm not all that great with electricity. . . What do you feel is a pro/con of your setup vs. mine?

They seem virtually the same, I just used one less relay to accomplish the same thing. I haven't checked at the fan to see if it has constant ground and is switched with power, or constant power and is switched with ground. I wrote up the diagram under the impression that the stock aux fan is switched on by ground. If that's not the case a couple of swapped wires on the relay on the right of the diagram will fix that. Definitely use 40amp relays and you'd be wise to use an 80 amp relay for the high speed side as it's got a pretty high current draw on it at startup and once running also. A 40amp might work, but it's going to burn out eventually and leave you fanless. I prefer to overbuild things a bit, and if you go with the wiring I did above you'll have to buy one less 40amp relay anyways. You could also add a switch in anywhere you wanted in order to turn the fans on by tripping whichever relay to control whichever speed of the fan you wanted switched on.

I just found a fan from a 95 Taurus SHO. Will that one work?