The Correct Way to Wire an Electric Fan
 

Here It is...
https://www.rx7club.com/attachments/...-efanwires-jpg

Dont agree on the one speed diagram. If the temp sensor was to fail (closed), your fan would stay running constantly. Murphy's law dictates that this will happen while you are on vacation/business travel, or spending the night on a booty call LOL

I prefer to wire 86 to accesories (ignition 12v)

I agree, I have mine wired into a racing switch to ensure a fail-safe if the thermostat sensor is on the fritz.

86 could also be wired to accesories, you could evn hook 86 up to a coil +

Thats what I said :icon_tup:

Weird nobody liked my booty call moment lol Yall been there, where all you want to do is leave, only to find the car with a dead battery :lol:

Do you speak from experience?

I wouldn't recommend using the coil + for running the fan. Maybe for activating a relay, but not for actually powering the fan. This can lead to ignition issues (spark knock) at high rpms when the fan is running.

Yeah, I still need to fix mine. :) That is how I have mine wired right now, and that is the issue I'm seeing. I've picked up a relay to install so I can do it right, just need the time to get it done...



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Why not install the temp sensor on the e-fan ground, instead of on the relay. In addition, i will add a second wire on the e-fans ground wire to q toggle switch to turn on the fan anytime you want it "on.". Lastly, i will install the t-sensor on the lower rad hose. Btw what brand temp sensor are you using?

86 does'nt power the fan, pin 30 does...

https://www.rx7club.com/attachments/...tive-relay-jpg

#1 the idea of have the temperature switch trigger the relay is so that the temp switch does not have to carry the amperage load of the fan. Most temp switches are rated to handle a fan however, including a relay will increase the reliability of the system. Also, most temp switches are only rated for 30-40 amps...

#2 A toggle switch could be used. However, usually when this temp switch fan your fan stays on not off. A toggle switch could help in racing applications, but the in any case where your car has a thermostat you don't want your fan to run continuously. In most racing applications a lower temp thermostat is used. as a rule of thumb your E-Fan should turn on @ 10 F higher then when your thermostat opens.

#3 These diagrams where made for a simple 2 wire switch. The idea is simple, the switch has continuity when the set temperature is reached which triggers the relay and turns on the fan. Here is the one I used:

You can find this adjustable temp switch pretty much anywhere, I got mine from NAPA. This is the push in probe type, you can also use an inline coolant temp switch. Here are more part numbers:
Flex-a-lite 31147
Painless Performance Products 30112
JEGS Performance Products #555-52125

#4 You want to put the temp probe as close to your water inlet as possible since that's where the coolant will be the hottest.

If anyone has any questions just let me know hat you have and what you want and I'll do my best to help.

1: relay or fan, it doesnt matter. you will have a load on either location.....negatively grounded. However, for me, it will not be on the relay.
2. toggle switch on the ground wire will allow you still have an e-fan in case the temp switch goes it....a peace of mind.
3. I prefer the bottom hose since I want to monitor temp of coolant entering the motor.

The purpose of the relay is so it will carry the load instead of the switch, this way the relay carries 30-50 amps and the switch carries less than a half an amp thus prolonging switch life.


Although it’s true that you could have this relay switching ground as opposed to positive for an aftermarket fan, this is not possible when using a Taurus fan since the high and low share a common ground. In that case your fan would spin backwards…


It’s true there are other correct ways to wire an electric fan, but these ways I have here are
the most common, this thread was put together to help people wire their fans. A switch could be added for peace of mind if you wish. However, since I understand this circuit I know that if the temp switch were to fail (I have not had mine fail yet as of 1 year) I could just pull the terminal on 87 and put it on 87a for a continuously running fan. It’s true that I would still have to open my hood but I prefer not to add extra and in my opinion unnecessary switches.


One more thought, others suggest connecting contact 86 to ignition 12v but for me I wire it to battery to minimize heat soak and prolong engine life. It usually runs for about 30 seconds after I shut the car off.

From the dead . Good info I'll be using soon

If youre using a volvo fan relay to control a taurus fan, low speed can be controlled by grounding the fan relay via a thermo switch. also you can be creative by adding a piggy back a wire with a toggle switch on the same thermo switch to turn on the low speed and a separate toggle switch for high speed but not necessary if you have a 3row or an aluminum radiator for DD. This is how i did my RX-3s as well as the SA and FB.