rolledthatho

i want to hard wire my fan to a toggle switch so i can control when its on or off. how do i do this? the cheapest easiest way possible (its a beater to the max haha)

radex7

Are you talking about the radiator fan or blower? For the first one easiest would be to bypass existing circuit (it goes through ignition, some relay, and a fuse box i believe) and just run a couple of wires, one to the ground, the other from a power source to the fuse, then to the switch, then to the fan motor. That is the simplest circuit I can imagine.

rolledthatho

hey man sorry im talking about the radiator. yeah thats what im trying to do 2 wires one hot one ground lol i justs didnt know how it would work, or where i would even begin to find those wires on the radiator? is there a plug coming off the radiator with 2 wires i just need to cut/splice and run those into the toggle?

gringo7718

Easiest and best way is to find the thermostat fan switch on the back of the block. There are two wires going to the fan switch (+ yellow/green and black -). Tap a wire into the + yellow/green wire and run it to a switch inside the cabin. Ground the other end of the switch and you now have a switch to turn on your fan whenever you want and the best part is that it will not interfere with normal fan operation.

The coolant temp fan switch on the back of the block is a low amperage sensor that when it gets to a certain temperature, it grounds out and triggers the factory relays which power the fan. The method I suggested uses this coolant fan switch to trigger the factory relays to power the fan. The idea is to manually ground out the sensor with a switch and use the factory relays to turn the fan on. The current used to power the fan still flows through the factory relays and not through this circuit, so there is no problem with the switch overheating. The fan will be powered using the factory relays etc. so there is no need for additional relays.



The purpose of doing this allows the user to retain the functionality of the factory setup, as well as the option to turn on the fan in an emergency or in between runs.

shaggyeg6si

OP, why would you want to do this anyway? At high speeds, like highway, it'll overheat. I did this in the past because I ran a EG radiator, and anything over 75, the car would overheat. I just fixed it and put it back to normal and have had no problems since.

hondacivic90zc

My hatch as the fan running off of a switch located in the cabin. My car never overheats and I often cruise at a little over 75mph. You don't have to have the fan on all the time. I rarely even use mine(normally only when I am sitting idle in a drive thru or traffic or something) and it always stays slightly below the middle on the temp gauge.
Now to the op, I cut the ground wire for the fan right near the battery and just grounded it directly to the negative battery cable. I then took the positive wire and ran it into the cabin to the fuse panel under the dash, found a slot that was switched power and not in use and just used that to power it. Make sure you get a switch that can handle the amperage though cause mine tends to get hot if left on to long, that reminds me I still need to change that out haha.

shaggyeg6si

Well to be fair, mine wasn't ran on a switch, I went straight to the battery and unplugged it ghetto like every time I stopped at a place.

gringo7718

The thermostat fan switch turns on the fan and uses low amperage. By doing what I suggested, you still retain all of the factory relays to power the fan at the correct amperage etc. It is really easy to use a switch, tap one wire into the + wire of the coolant thermostat switch, and the other to ground. This is well established as much safer, better, and easier than any other solution posted here.

radex7

This is definitely more sophisticated solution. Nice.

rolledthatho

thank you gringo ill try that!

rsnupt82

yea thanks gringo, i'm starting to over heat my b16 when i have the a/c on and i'm idle for 10 mins. kinda wack cause i bought a new thermo stat switch...

D16SiHatch

You wouldn't have the issue of the switch overheating if instead you hooked the fan up to battery voltage in the engine bay. then run a ground wire from one side of the fan switch into the car to your rocker switch. no worrying about shorting anything out or overheating a switch if its only connecting a ground.

i am confused though as to why someone would want to do this.. if the fan switch and coolant system is functioning properly, you should never have a need to manually turn the fan on.

gringo7718

You completely missed what is happening here. Who ever said anything about my switch overheating???

I will try to clarify this again so you can understand. The coolant temp fan switch on the back of the block is a low amperage sensor that when it gets to a certain temperature, it grounds out and triggers the factory relays which power the fan. The method I suggested uses this coolant fan switch to trigger the factory relays to power the fan. The current used to power the fan still flows through the factory relays and not through this circuit, so there is no problem with the switch overheating.

sh!ft

i hooked mine up to my amber lights so they come on when i turn on the lights

blazzer

weird thred i bought my rex alreay wired up with is being attached to the igniton kinda dumb but w/e i rewired so it works propery back on the coolant temp switch


in confused as to why you guys do this the point of the collant switch is so it tunrs on when needs if you havea switch in your car you dont really know exactly when to turn it on precisly when the engine needs/wants it

in my opinion kinda eleminates the point of "engine-rad-fan-cooling"

if some one could explain what the real purpose is and how it affects things that would be good just doesnt seem really logical

jdmkid37

[QUOTE=blazzer;38956297
if some one could explain what the real purpose is and how it affects things that would be good just doesnt seem really logical[/QUOTE]

In case of an emergency overheat your car can still make it home.

SC_HOBD_1816

i think people do this becuuse they don't have money to buy the spoon or mugen low temp sensors plus i think it's better or not. by letting the fan run it will cool your engine and engine bay.
Spoon and Mugen thermo switches are located were the oem is located and they are low temp, they turn on @ a lower degree for cooling purposes. I'm not sure how it will effect the car but i see that there is going to be more energy and volt generated from the fan being on.

blazzer

that kinda makes sence thnx to!!

jhammond_82

iTrader: (1)

i'm still at a loss as to why you would want to bypass the fan relay if all is working as it should? i mean, honda put that there for a reason. if it doesn't work, try changing the relay, or temp sensor. if it aint broke, don't fix it!

D16SiHatch

trust me i fully comprehend the inner complexities of this fan switch. its not a difficult concept. it achieves continuity and allows the relay to be grounded at a temperature of 190-203 fahrenheit. and it will lose continuity as the temperature drops to between 182-188 degrees fahrenheit.

i was replying to hondacivic90zc's post, #6, not yours.

FOMULA91

iTrader: (3)

Good information. My fan is also wire to a switch and it is connected directly to the batter (ghetto style) and Ive been running like this for 4 years but differently do it your way...

However, I rarely use my fan because normal driving will cool the motor by itself... The only time I really use it is during traffic and that's the time when I see the temperature gauge go up slowly....

Mr.Death

I have mine wired up like so. I cut off the sensor plug that goes to the thermostat which (we all know activates the fan when the sensor reaches a certain temp) and ran the two wires to the cabin to a switch. Turn the switch on and the fan activates. I see no problem with this set up.

zrickety

iTrader: (1)

bad idea to just use a switch...something could melt and catch fire.
at least use those wires on the engine temp switch. then it is running thru the proper relay and fuse. it's just as easy or easier, if you HAVE to have a switch.

personally, the stock setup is the way to go

sh!ft

thank you very much captian obvious, if that were the case then there would be no point to this site (facepalm) this individual wants to know how he can always run them. not as close to stock as possible

beana

it's best to leave it stock, or change your coolant temp sensor or just repair the wires because i have a feeling you want to do this because something is wrong

it's best to leave it stock, for two reasons:
1: you're not paying attention the gauge, and it overheats, your head's screwed and maybe your block too
2: if it's always on your car will run rich, because of the same reasons it does when you don't run a thermostat, the engine won't reach normal operating temp, and the computer will keep dumping fuel in an effort to heat it up