Running an IC fan constant

Dahoopd

Registered User
Would it be worthless to run the IC fan all of the time. I am not aware of how the air forced into it while driving would effect it. I would prefer to not flip a switch on at idle every time I stop.
 
I put a toggle switch in the console that goes to the relay for the IC fan so I can turn it off during the Florida winter when it gets into the 60s at night.

While I was at it, put in a 2nd "blank" toggle switch and ran the line under the hood just in case I add something later that can use a switch.

eddie
'90 5-speed SC
'97 LX sport
 
The ic fan on my 90 runs with key on. I put the fuse for it up by the battery, so when the ambient air drops in october and it's 40f in the morning, the fan doesn't need to be running I just pull the fuse.

For drag racers, I'd wire it up to take power right from the battery, and the relay is switched from inside the car also ganged into the ignition. Using a double acting switch, you could have the fan come on with ignition in one position, and then with the switch in another position, it runs with the ignition off, i.e. cool down after a run down the track.
 
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imo if you have an ic fan, have it on all the time. mine has a manual key switch just incase if i need to turn it off, otherwise its on all the time.
 
Below is a diagram that I worked up if you wanted to have a switch that allowed you to choose between always on (even with key off) or just run when the key is on.

To do this you need a switch that supports double throw independently.

You wire the switch up so that the common goes to the relay fan control (typically connector #87 or #86 on a Bosch style relay) and the switched outputs become inputs. One from an ignition switched 12v source and one from an always hot 12v source. The switch when put to one location completes the circuit that is 12v all the time and will run your fan with your engine off to just cool down the car. Then if the switch is in the other position, the fan will only run when the ignition switch is on.

run this all through a relay and you'll be good.
 

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kind of off topic but, shouldnt the fan run constantly regardless of wether its cool out or not ? i mean with the fan off its gotta make some kind of restriction just sitting there not pushing or pulling air.

am i right ?
 
kind of off topic but, shouldnt the fan run constantly regardless of wether its cool out or not ? i mean with the fan off its gotta make some kind of restriction just sitting there not pushing or pulling air.

am i right ?

I'm sure it performs some level of restriction, but in general, you're gonna turn the fan on anytime you are driving in a way where you want high performance. Any other time, you're not likely into boost, and if you are, you aren't worried about loosing some HP to high intake temps.

That is for a car that isn't on the ragged edge of performance. A ragged edge performance car hopefully is owned by someone that knows what they are doing.
 
Just installed my IC fan last Friday. Put a switch inside that little cubby underneath the HVAC controls. The fan will run whenever the switch is on and the key is in run. I just leave it switched on all the time though, maybe I'll shut it off in the winter. I figure a little bit cooler intake temps could always help!
 

Switches...switches. I need to fill in the back area yet with a beauty plate, but what I have are 2 switches on the left are 3 way switches. Right two are two way switches. (the jack in the picture is part of my fitting things in the car to go drag racing and camping with a trunk full of coolant tank, pump and battery.)

left to right
Intercooler water pump
Intercooler heat exchanger fans
Snow System Enable
Line Loc Enable.

The two on the left if pressed down, as shown in the picture turn on the pump and fans with the ignition switch. If put in the middle they turn of completely. If pressed all the way forward, they run with the key off. The right two are simple on off. The snow one powers the snow controller directly, basically acting as a open when not enabled. The line lock one acts as an open between the button on the shift handle and the relay for the line locs. With the switch disabled, pressing the button on the shifter does nothing. Enable it, then press the button on the shifter and the light on the switch comes on as well as the line locs.

How I did the two left switches is that these switches support one input to two outputs, which I reversed as two inputs to one output. One input is wired to keyed power, the other wired to always on power. The output actuates a relay.
 
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