How-To: Fan Switch Mod

2001DodgeNeonSe · Post by **2001DodgeNeonSe** » Sat Apr 28, 2007 2:38 pm

HOW TO: Fan Switch Mod by IEATVTEC

To save myself from carpal tunnel syndrome, here is a how to on the fan switch mod.

Im going to try to explain this as if I were talking to a bunch of idiots. I was always taught in grade school to do that. That way, everything is covered and there 'shouldnt' be any questions.

This mod will allow u to turn ur cars main fan on at will, with the simple flip of a toggle switch. Mostly beneficial for the dragstrip while waiting in line to drag, to keep coolant temps down. Remember, coolant also runs thru the turbo and having a cooler turbo will yeild more efficient power. *works best in conjunction with the 180 or 160 degree t-stats. available from Howell Automotive. I personally recommend the 160, but if u live in antarctica, get the 180.*

Things needed:

Wire strippers
electrical tape
5 amp fuse
roughly 10 ft. of 18-20 gauge wire, nothing big
small, two wire/prong toggle switch
small metal rod for running wire thru firewall.
15 minutes of ur time

First, if u have the stock intake u will have to remove the airbox portion. This is easy and makes getting to the wire u need alot easier as well.

Locate bundle of wires (loomed and taped) directly above stock computer. This bundle, roughly an inch in diameter, is pretty much right above the top of the computer if ur standing in front of the car.

Stock computer is located directly below stock airbox.

cut away loom and tape on bundle and locate BLUE WIRE WITH PINK STRIPE. Not light blue, not navy blue, not the new 04 SRT blue...just a medium blue.

Once found u need to test the wire to make sure its the right one. Im pretty sure its the only blue/pink wire in that bundle, but test it anyways for liability reasons.

TO TEST: rig up a simple 2 foot wire with inline fuse. Take a scrap piece of wire and cut it in half. strip back one end of each wire and wrap around either prong of that 5 amp fuse. (doesnt have to be five amps, but should not be any more than 7.5)

Make sure that each wire end u have wrapped around the prongs of the fuse dont touch each other...that would defeat the purpose of the fuse.

Now, strip back some sheathing on the blue/pink wire. connect one end of ur inline fused wire to the blue/pink wire. Connect the other end to a ground inside the engine bay.

Cars ignition must be turned to the on position for this test. I recommend having the car already on BEFORE u touch the wire end to ground. That way if the fuse is going to blow, which would be immediate if the polarity wasnt right, ud catch it instantly.

once the car is on and u have either end of ur fused wire in place and the fuse doesnt blow, keep each end where they are and the fan should kick on in around 5 seconds or so.

u have just correctly tested for the wire. Im pretty sure its the only blue/pink wire in the upper most bundle coming off the computer, but test it anyways. dont just hook up a wire cuz someone says so.

Now u can hook up ur 10 ft of wire to the blue/pink wire and run it thru the firewall. (Verdict1 and myself always recommend relooming and taping all wires/bundles u deloomed and detaped.) To be neat and to keep ur mod discrete.

Thru the firewall, Verdict1 and I recommend going thru where the vacuum line for the boost gauge goes thru. Directly behind the battery on the FW ull see a single line, by itself, wrapped in foam.

Using ur metal poking rod, tape the other end of the 10 ft wire u connected to the blue/pink wire to the rod and 'poke' it thru the grommet.

Once thru all u really have to do is find a place to mount the toggle switch, hook up the line u ran thru the firewall to one side of the toggle and connect the other side of the toggle to ground.

Verdict1 and I have our toggle switches mounted in the rear of the pocket between the rear def. switch and the 12v acc. out socket.

***stage 2 people using the turbo toys hardware may want to find another location, since the pocket will be filled with other things.***

The rear of the pocket provides a fully hidden location. Plus, there are already two clean holes already in the rear of the pocket.

To access pocket, pull down on air vents above radio with slight pressure. They will pop out revealing two screws at the top of the vent mounts.

Remove all four HVAC knobs and firmly pull on entire trim piece to remove. Grabbing divider piece that seperates air vents is best.
*if HVAC knobs wont come off, just begin removing trim piece...they'll pop off easily*

two screws hold in pocket...remove pocket and install toggle switch in one of the predrilled holes.

connect line that u ran thru engine bay to one side of the toggle and tap the other side of the toggle to ground. U can use the black wire on the 12v acc. outlet plug to the right of the pocket for a ground.

Again, if u choose another location, just find a good ground and hook up the other wire as described above.

be sure to hide all wires and do a clean install. If you dont u suck.

Thats pretty much it.

while at the track waiting to drag, keep car running, hood opened, and the defroster on. This will keep coolant temps ultra low, especially if u have a 160 t stat. U can run the a/c too instead of the defroster, but then u get all cold and the shift knob feels slippery and to hell with that. The defroster turns on the a/c, but doesnt get the inside of the car all cold...plus it cranks on the secondary smaller fan inside the engine bay.

Good luck and dont mess anything up. This is a very simple install and should cost u next to nothing.

If u have the 160 t stat and are idling for long periods of time, like say in traffic, use the switch to keep temps under control, until u can get moving again. They will safely rise above 200 degrees, but ull see once u start moving, the temps drop quickly (with 160 t stat).

enjoy

MoparNeonMan · Post by **MoparNeonMan** » Sat Apr 28, 2007 8:16 pm

Sweet! I smell a project for next weekend. Now what about the secondary fan? Cant you have that come on as well?

TheNumberOneD · Post by **TheNumberOneD** » Tue Jun 26, 2007 8:50 pm

does anyone know which wire it is on the 05? cause its definatley not the blue and pink stripped one... lol

also, the ecu is diffrent from the one on the 01 model, so anyone who has done this on an 05 model i'd appreaciate it.

Summer heat in texas sucks, and so does traffic

Post by **Diablo0** » Wed Jun 27, 2007 12:31 am

Should be exactly the same for an '05. You can also tap into the PDC under the hood at the at the Fan Relay. This mod does work great though, just did it this past weekend on the white car. To get the other fan to come on all you really need is a small jumper wire between one relay to another so when one is grounded with the switch so is the other one. I'll post a diagram tomorrow...

BlackRoseRacing · Post by **BlackRoseRacing** » Wed Jun 27, 2007 6:41 am

Also someone post some pics of this how to....
The detailed instructions are nice, but pics will help even better...

03sxt · Post by **03sxt** » Wed Jun 27, 2007 9:14 am

BlackRoseRacing wrote:Also someone post some pics of this how to....
The detailed instructions are nice, but pics will help even better...

jprince · Post by **jprince** » Wed Jun 27, 2007 9:21 am

but with the switch in the off pos. will the fan stillw ork under regual conditions, ie, still come on automatically.?
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soccerdanno · Post by **soccerdanno** » Wed Jun 27, 2007 9:44 am

Cool mod. Thank you for the write-up.

Post by **Diablo0** » Wed Jun 27, 2007 10:43 am

jprince wrote:but with the switch in the off pos. will the fan stillw ork under regual conditions, ie, still come on automatically.?

Yes, all you're doing is forcing a ground to the relay making it kick on. When it's off then it functions normally.

Also, pictures... there really isn't much to show other than which wiring loom to look for the wire in...

jprince · Post by **jprince** » Wed Jun 27, 2007 1:25 pm

ok lol i looked for the wiring could someone please post a pic im really interested!
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TheNumberOneD · Post by **TheNumberOneD** » Wed Jun 27, 2007 10:01 pm

ahhh, well the ecu is diffrent, so i couldn't figure out which split loom to crack open. First blue and pink striped one i found, i tryed to ground, and got nothing but a bunch of sparks and a messed up idle.

Thankfully i didn't permatley mess up anything electrical, i'll make sure to ask for more info before i try anything ever again

Post by **Diablo0** » Thu Jun 28, 2007 12:08 am

I don't have a pic yet but if I remember right it's the loom that comes right from the PCM and loops up then heads into the main harness which goes into the PCM. Make sense?

jprince · Post by **jprince** » Thu Jun 28, 2007 5:46 pm

ok on my car 02, there the pcm dr. side, then there are 2 on top pluged into the pcm one head towards the engine and the other behind the pcm. then there is one i found that went up the side of the pcm to the fuse box. found a blue pink wire did the test but nothing happened, now i had a 10 amp fuse... was the the prob.? it calls for a 5 amp, but really a ground is a ground and the fuse is just there to save ur ass. So i think i had the wrong harness??
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TheNumberOneD · Post by **TheNumberOneD** » Sat Jun 30, 2007 9:41 pm

Diablo0 wrote:I don't have a pic yet but if I remember right it's the loom that comes right from the PCM and loops up then heads into the main harness which goes into the PCM. Make sense?

yhea the one that kinda loops over the throttle body ? and run along the right side of the valve cover?

( i hid mine under the throttle body, for a cleaner look)

If so, that blue and pink stripped wire is the same one i tryed, and all it did was mess up my idle.

And yes i was putting it to the negative terminal on my battery, not the positive.

perhaps its diffrent....