How can i hardwire my Fan to always run

 
Old 06-19-2009, 08:10 PM
  #26  
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Default Re: How can i hardwire my Fan to always run

Wow.
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Old 06-21-2009, 12:37 AM
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Default Re: How can i hardwire my Fan to always run

Originally Posted by gringo7718 View Post
Easiest and best way is to find the thermostat fan switch on the back of the block. There are two wires going to it (yellow/green + and black -) tap a wire into the positive and run it to a switch inside the cabin. Ground the other end of the switch and you now have a switch to turn it on and off at will.

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.
this is the right way to do it. but unnecessary, read below.

many ppl are not reading carefully or just dont understand this method. to reiterate, nothing can get burnt out or overheated by this method since it is simply over riding the stock sensor. it does however use the fan more and could cause it to fail sooner if its left on too long. it will not cause the engine to run too cool since that is what a thermostat is for. and will not allow the engine to overheat since the stock sensor will still work normally, so when the engine needs the fan, it will still turn on by itself.

however, what really does running the fan accomplish? if the stock components ARE working properly, the engine will be fine as is. if the purpose is as mentioned "between runs" like with the engine off, turn the fan on, this does very little to cool the engine really since the water from the radiator is not flowing with no running water pump. youre really just blowing air to the external of the engine, but i dont think this does much really and not needed since the engine should not be overheating anyway.

its nice to be able to control things that are out of the users control with a button, and i have done this myself even, but when you really think about it, it doesnt do anything.
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Old 06-21-2009, 12:41 AM
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Default Re: How can i hardwire my Fan to always run

btw, i used a stock 88-89 rear defroster button in place of the blank spots in the underdash area. fits like its made to be there. and has a useful indicator light if you wire it properly. oriented vertically, the icon even looks like a fan function... the same button can be used for any other myriad uses for a switch. without looking aftermarket and quite frankly ugly and out of place like gringo's choice of switches.
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Old 06-21-2009, 12:51 AM
  #29  
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Default Re: How can i hardwire my Fan to always run

Originally Posted by beana View Post
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
I got my hatch with the fan always running. What are some symptoms of a car running to rich? Cause maybe this is why my car runs like it does. But the tmp gauge will go up to about half way. Almost.
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Old 06-21-2009, 08:05 PM
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Default Re: How can i hardwire my Fan to always run

Originally Posted by skipbudlong View Post
I got my hatch with the fan always running. What are some symptoms of a car running to rich? Cause maybe this is why my car runs like it does. But the tmp gauge will go up to about half way. Almost.
if it's running really rich it's easy to tell because you'll smell it from your exhaust, smells like gas but with a burnt smell to it, if it's running slightly rich it's more difficult, but you'll notice a slight decrease on the butt dyno, like when you know it's not running right
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Old 06-25-2009, 04:38 PM
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Default Re: How can i hardwire my Fan to always run

there are 2 ways to wire the fan...the right way (with relays, like stock) and the wrong way.
unfortunately, i see most ppl wire them up the wrong way. switches, or hard wiring to god-knows-where. worse yet, it's unnecessary.

FYI, if your car came with a/c and you don't use it, you can jump the pressure switch and then your a/c button can turn on the fan.
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Old 06-25-2009, 04:51 PM
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Default Re: How can i hardwire my Fan to always run

Originally Posted by zrickety View Post

FYI, if your car came with a/c and you don't use it, you can jump the pressure switch and then your a/c button can turn on the fan.
lol. if youre gonna do that, just do it like was described earlier and jump the ACTUAL fan switch.
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Old 06-25-2009, 05:18 PM
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Default Re: How can i hardwire my Fan to always run

lol. jumping wires could lead to other retarded issues. when i had a vw back in the day, i had to jump the fan wires. well, then i blew a fuse, and some of the wires i guess melted and what not. my windshield wiper switch made the horn blow, the horn button made my head lights flash. it was messed up. installing a switch is ok, but what about the ONE time you forget to turn it on when you get into your car? you'd be SOL. overheating issue, blown head gasket, ect.....
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Old 06-25-2009, 05:19 PM
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Default Re: How can i hardwire my Fan to always run

if you read carefully, thats really not the type of jumping of wires being talked about.
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Old 06-25-2009, 06:03 PM
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Default Re: How can i hardwire my Fan to always run

hmm...the first page i believe it was referred to a few times. i know what you guys are saying now, but i was referring to what was previously. sorry, i'm bowing out of this thread now, i don't like walking on egg shells.
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Old 12-25-2013, 11:26 AM
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Default Re: How can i hardwire my Fan to always run

1996 Integra Non-Vtec motor, I've got my both my fans running with the relays in but for some reason my radiator fan will stop and my air conditioner fan will continue only if it's clicked on in the dash. Now I was wondering if there's a solid way to wire straight off the fuse box to the the fan motor so that it runs only while the engine is kicked on, so as not to drain the battery. Since it's only a 4-Cyl I figure it would be fine without a switch to toggle it on or off, but would you still recommend having a switch installed between the points or do you think it would be safe to run without one?

Secondly, once my fans are both running again I have to make sure everything is flowing correctly. I had some overheating recently, just swapped out the old thermostat and it still overheated way too quickly. I believe the air has been fully bled out of the radiator and it has adequate cooling fluids. Water pump hasn't given any immediate signs of damage (IE no leaking, no noise) Any ideas as to what I should be checking next?
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Old 12-25-2013, 12:44 PM
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Default Re: How can i hardwire my Fan to always run

Took a test drive with both fans on while the relay in the cooling fan spot, not the air conditioning (have to wait till tomorrow to find another one) and after a drive to warm it up the fans turned off. When we parked and checked them again the fans turned back on only after I flipped my A/C off and on again.. So for some reason they are quitting sometime while it's on the road although they start back up and were running for me before we left. (Note: A/C in dash was ON, but only to get fans to work. There wasn't a relay plugged in the A/C spot in my fuse box.)

Any ideas as to what would cause them to act like this?
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Old 06-18-2015, 01:10 PM
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Default Re: How can i hardwire my Fan to always run

Sorry to resurrect, but I am having an issue with my 91 dx sedan cooling fan. The fan works with direct power but does not turn on when driving. Replaced relay, then it worked, then failed again. My buddy has recommended wiring the fan to a toggle switch. My experience tells me that the motor itself needs to be wired to a switch, I have wire and a switch. Now, to my understanding, I have a blue wire and a black wire running to my cooling fan motor. I've been told to run 2 wires from the positive wire (and leave the current ground alone) which I'm assuming is the blue wire, through the firewall and lead the wires to an indash fusebox opening that receives power, then to the toggle switch.

Could somebody clarify this information for me I'm horrible with electrical systems lol.
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Old 06-18-2015, 01:43 PM
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Default Re: How can i hardwire my Fan to always run

Originally Posted by jmanjdm View Post
Sorry to resurrect, but I am having an issue with my 91 dx sedan cooling fan. The fan works with direct power but does not turn on when driving. Replaced relay, then it worked, then failed again. My buddy has recommended wiring the fan to a toggle switch. My experience tells me that the motor itself needs to be wired to a switch, I have wire and a switch. Now, to my understanding, I have a blue wire and a black wire running to my cooling fan motor. I've been told to run 2 wires from the positive wire (and leave the current ground alone) which I'm assuming is the blue wire, through the firewall and lead the wires to an indash fusebox opening that receives power, then to the toggle switch.

Could somebody clarify this information for me I'm horrible with electrical systems lol.
START A NEW THREAD!
(next time)

I think you should just fix the problem. It's really not that complicated.

Fist, check the #15 fuse in the dash fuse box.

Next, disconnect the fan and run it directly to the battery with jumper wires to make sure it spins (doesn't matter if you get the wires backwards as it will just spin the fan in reverse - the test is just to make sure the fan motor is in good working order before moving on).


The most common issue is the coolant temp switch failing.
One wire for this switch goes directly to ground at the thermostat housing. This is ALSO a common issue so check the grounds wires to make sure they are in good condition and tightly attached to the thermostat housing. (see this pic for location http://breebamboo.ipage.com/archive/...oundstraps.jpg)
The other wire on the switch goes to the relay.
So, when the switch gets hot, it closes the circuit and provides ground to the relay. <- this is THE wire you would want to add an in-cabin manual toggle switch to. Always avoid running + power to a switch! Toggle switch would have a short wire on one pole going directly to chassis ground in the cabin and the other pole would have a wire running through the firewall spliced into this coolant temp switch wire.


Here's what you do for trouble shooting the system (after checking the grounds at the thermostat housing):
Go to the coolant temp switch and disconnect it. (Take a look at this pic for the location of the switch by the oil fiter http://www.redpepperracing.com/galle.../LSSensors.jpg It should have a big black boot with two individual connectors for the two wires.)
Using a paperclip, jump the two connector wires together(not the switch, but the wires in the harness) to short the wires together.
This will simulate the switch being closed and will send ground to the relay.

Turn the ignition to ON position (no need to start the engine) and the fan SHOULD come on.
If it DOES come on, then your thermo switch is bad. Replace it and you are done.

If the fan does not come on, then touch the paperclip to the engine or chassis.
If the fan comes on, then the ground wire to the thermo switch is bad. Replace with a new ground wire. done.

So if the fan didn't come on yet, then the relay is suspect.
With ignition on, you should have + power on both BLK/YEL wires.
Injecting + power to the BLU/BLK wire should power the fan on.
When the coolant fan switch is closed (or when you have a paperclip shorting together the two temp switch wire) then you should have ground on the BLU wire.


See where you can get with all that info.
Feel free to come back if you need more help. (starting a new thread that time)



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