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Best way to do E-Fan

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Old Apr 4, 2012 | 10:22 AM
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Best way to do E-Fan

Hey guys,

I have an E-Fan setup on my turbo car from the previous owner. Yesterday when I got home from work I noticed my car was a little hotter than normal, about 1/3 up the gauge vs the typical 1/4; turns out my E-Fan never came on.

After realizing some of the wires have burnt themselves at the connectors do to excessive load, I wondered if there is a better way to wire the E-Fan.

Currently, the fan is wired to a 180 degree temp sensor located behind the water pump. The problem with this is since the temp sensor is in the block, the moment the block warms up the E-Fan comes on; meaning it does not shut off once it comes on and the car is running. After I turn the car off, it continues to stay on until the block cools down, which could take 20 minutes.

Is that the normal way of doing things? Is there a better way of doing it? How can I prevent the wires from eventually burning up again? I have heard of coolant hose adapters so you can have a switch in the coolant hose. Is that better? Thanks for any help.

Here is a pic of my car:
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Old Apr 4, 2012 | 11:41 AM
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Are you using any relay's or are you hooked directly to the sensor? Your post is not clear.

A 1/4" spade connector is rated at 30 amps max. If your fan pulls more (or even close) you will get some heating. Eventually you get melting. Solution is to use a high amperage relay that has 3/8" connectors for the load. Proper crimp or ring connections other places will eliminate the heating.

Also, pull those 4 studs out of the waterpump hub. Those things will wind you up if you ever get too close.
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Old Apr 4, 2012 | 01:26 PM
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Originally Posted by jackhild59
Are you using any relay's or are you hooked directly to the sensor? Your post is not clear.

A 1/4" spade connector is rated at 30 amps max. If your fan pulls more (or even close) you will get some heating. Eventually you get melting. Solution is to use a high amperage relay that has 3/8" connectors for the load. Proper crimp or ring connections other places will eliminate the heating.

Also, pull those 4 studs out of the waterpump hub. Those things will wind you up if you ever get too close.
Thank you that is very good info

I am using a relay btw, with ground going to a 40amp fuse in the fuse block.

Pic of relay:
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Old Apr 4, 2012 | 01:58 PM
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I'd look into a temp switch with a higher setting once the wiring issues are sorted. I think having it come on at 180F is too cool.
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Old Apr 4, 2012 | 02:00 PM
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This is what you need:

http://www.parts-express.com/pe/show...number=075-140
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Old Apr 4, 2012 | 02:10 PM
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Thanks for the info guys

Question: Is it good to have the temp switch behind the water pump in the block? Or should I move it to the upper radiator hose before the T-stat?
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Old Apr 4, 2012 | 02:13 PM
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What temp switch are you using? Edit: Nevermind, I see in your first post that the switch is 180*.

I am using a 195* switch in my radiator inlet. It does the same as yours does in warm weather. I have the control current wired so that when the key goes off, the fan goes off.
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Old Apr 4, 2012 | 08:54 PM
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Here is a solution. Put the clutch fan back on and be done with it. E fan doesnt do much for you anyway besides use more voltage. You wont get more power from it so it is pointless. The only thing it may be good for is to clear up space under the hood.
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Old Apr 4, 2012 | 09:24 PM
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Originally Posted by R0tor R00ter
Here is a solution. Put the clutch fan back on and be done with it. E fan doesnt do much for you anyway besides use more voltage. You wont get more power from it so it is pointless. The only thing it may be good for is to clear up space under the hood.
Here is where I iterate that after owning 8 FCs, not having a fan clutch and radiator shroud to deal with gives me a humungous boner

Anyways, I am not here to debate whether or not to use one, I am here just to ask where the optimal position to put the switch is. Any info would be great
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Old Apr 4, 2012 | 10:08 PM
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8 FC's? who r u ?
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Old Apr 5, 2012 | 05:36 AM
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Originally Posted by R0tor R00ter
Here is a solution. Put the clutch fan back on and be done with it. E fan doesnt do much for you anyway besides use more voltage. You wont get more power from it so it is pointless. The only thing it may be good for is to clear up space under the hood.
Clearly you know nothing about electric fans and how they can be operated.

@funkjaw:
One way to install the fan, here.
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Old Apr 5, 2012 | 07:53 AM
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That is the biggest relay I have ever seen!!! It's bigger than your battery!
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Old Apr 5, 2012 | 10:51 AM
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Originally Posted by clokker
Clearly you know nothing about electric fans and how they can be operated.

@funkjaw:
One way to install the fan, here.
Clearly you dont know how the fan system works on a rx7 and when it is neccessary to have a fan running or not. Read this and it might help you.http://www.aaroncake.net/rx-7/efanmyth.htm
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Old Apr 5, 2012 | 11:19 AM
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I disagree with your interpretation of Mr. Cake's article- your takeaway ("E fan doesnt do much for you anyway besides use more voltage") is much narrower than his and he even links to his own writeup on how to perform the conversion.

Anyway, as funkjaw pointed out, this is not a discussion about whether but how.
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Old Apr 5, 2012 | 11:20 AM
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I'm laughing at the giant relay
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Old Apr 5, 2012 | 02:47 PM
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Originally Posted by verrt
I'm laughing at the giant relay
Pretty cool, huh? Sitting right on top of that 2-story high battery.

I guess it's all really a matter of perspective.
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Old Apr 5, 2012 | 04:45 PM
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Originally Posted by clokker
I disagree with your interpretation of Mr. Cake's article- your takeaway ("E fan doesnt do much for you anyway besides use more voltage") is much narrower than his and he even links to his own writeup on how to perform the conversion.

Anyway, as funkjaw pointed out, this is not a discussion about whether but how.
That would be why I put that link up!
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Old Apr 5, 2012 | 05:39 PM
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wire your relay 12+ to an acc source and not straight to a 12+ constant. key off=fan off. also at such a low temp for the fan switch, i would put it in the back of the water pump housing. blowing off water in the radiator does little to water stagnant in the back of the block. especially if the engine is off.
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Old Apr 9, 2012 | 12:12 PM
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Thanks everyone for your help.

I will be:
-Putting switch in upper radiator hose
-Using a higher temp switch
-Using the better relay with larger spade connectors
-Feeding 12v off a non constant

Again, thanks for all the help.
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Old Apr 9, 2012 | 03:35 PM
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Question, if running the thermostat switch in the upper radiator hose near the radiator, what temperature should I use? I found a couple two prong thermostat switches on summit racing, one of them turns on at 195 and turns off at 185. The other turns on at 185 and turns off at 175.

Any thoughts?
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Old Apr 9, 2012 | 03:38 PM
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My fan trigger is in the upper rad hose, low speed turns on at 195°, high at 210°.
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Old Apr 9, 2012 | 04:01 PM
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Originally Posted by clokker
My fan trigger is in the upper rad hose, low speed turns on at 195°, high at 210°.
Do you have problems with the fan staying on too long after you shut the engine off? Or do you have it wired to only be on with ignition on?
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Old Apr 9, 2012 | 05:37 PM
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So found this unused bung on the bottom of my Koyo (probably because it is an NA S4 Koyo)

Wondering if that would be a good place to put a thermostat switch? The switch would be making no contact with the actual fluid. Any thoughts?

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Old Apr 9, 2012 | 05:56 PM
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From: And the horse he rode in on...
Originally Posted by funkjaw
Question, if running the thermostat switch in the upper radiator hose near the radiator, what temperature should I use? I found a couple two prong thermostat switches on summit racing, one of them turns on at 195 and turns off at 185. The other turns on at 185 and turns off at 175.

Any thoughts?
I'm using a Summit switch, single prong. 195* on 185 off, upper radiator tank near the inlet of the rad.

http://www.summitracing.com/parts/SUM-890018/

Originally Posted by funkjaw
So found this unused bung on the bottom of my Koyo (probably because it is an NA S4 Koyo)

Wondering if that would be a good place to put a thermostat switch? The switch would be making no contact with the actual fluid. Any thoughts?

No, the bottom of that rad will cause you to measure the coolant after it's already cooled. Your fan will not run till the engine coolant is way too hot at idle and slow rates of speed. I tried that location years ago by drilling out that well so the probe would contact the coolant. I installed a temperature sender for my VDO gauge to get an idea of the possiblities. The temps were very very erratic. Don't do it.
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Old Apr 9, 2012 | 07:02 PM
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Originally Posted by jackhild59
I'm using a Summit switch, single prong. 195* on 185 off, upper radiator tank near the inlet of the rad.

http://www.summitracing.com/parts/SUM-890018/



No, the bottom of that rad will cause you to measure the coolant after it's already cooled. Your fan will not run till the engine coolant is way too hot at idle and slow rates of speed. I tried that location years ago by drilling out that well so the probe would contact the coolant. I installed a temperature sender for my VDO gauge to get an idea of the possiblities. The temps were very very erratic. Don't do it.
Thank you sir!

Since you are in the radiator itself, I take it that is how you got away with using a single prong? I would imagine since I want to put it inline with one of those adapters in the upper radiator hose that I would need to get a two prong so I could ground it?
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