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Discussion Starter · #1 · (Edited)
UPDATE 07-07-2006
Warning - Hooking up power straight to battery may cause battery to drain. I left town for about a week and my battery drianed to zero. There is probably a better way to hook up power to the toggle switch. If anyone knows, please PM me and let me know.

UPDATE 07-11-2006
Come to find out, it was just a bad/broken battery. Sorry for the scare. But, I would recommend using a RELAY along with the SWITCH. Go to and look up "relay". It should explain how one works and from there you'll just need a little bit of electrical common sense.

This is a fairly easy, fun, and cheap way of making your own custom Intercooler Sprayer without having to spend hundreds of dollars on the STi or aftermarket sprayers.

NOTE: It looks hard to do, but it's much easier than it looks.


- Sharp knife or razor blade (box cutter)
- 10 mm socket wrench
- Phillips-head screw driver
- Good drill with a 1/4" bit

Supply quantities may vary depending on when and where you get them from

Walmart - Gardening Department
1) Drip Master Misting Nozzles (2 Packs, each pack contains 2 nozzles)
2) Drip Master Elbow connectors (1 Pack, contains 4 elbows)
3) Drip Master T connectors (1 Pack, contains 4 T's)
4) Plastic Ties (50 pack, more than you'll ever need for anything)
5) Hose - 1/4" (a huge 50ft roll, more than you'll ever need in your lifetime)

Radio Shack
6) Switch (choose whatever style you like)
7) In-line fuse (I chose a 30 Amp one just to be safe)
8) Quick Disconnects (1 pack, contains 4 pairs of male/female)

9) Ring Terminals (1 pack)

10) 18 gauge wire (1 roll)

NOTE: Make sure your ring terminals/quick disconnects are 18 gauge as well (or whatever size wire you decide to use)

Auto Zone
11) Washer Pump - See install for picture of what it looks like
12) Radiator Fluid Reservoir (You can use almost any container)

All items should run you less than $50

Step 1 - Preparing the pump and tank
Take your fluid reservoir and use your blade/knife to cut into it so that your washer pump will fit. See picture below:

Once you have a hole for it, you can insert the plastic washer that came with the pump and insert the pump into the hole.

Step 2 - Finding a place for the tank
Locate a place you want to put the fluid tank+pump and leave it there for now. We'll hook it up once we have all the wires in place.

There isn't much room in the engine bay for it. Some people have put it where their intake silencer is located. I put mine in the trunk. I moved my jack out of it's slot and place the tank+pump in it's place. I didn't mount mines, but it seems to stay sturdy and doesn't move around much so I'm not worried.

On a side note, some people don't even use an extra tank. They drill right into a pre-located spot on their window washer fluid tank.

Step 3 - Preparing your air splitter/shroud
Remove your air splitter. There are several obvious screws that hold it and two others are hiding behind the insulation.

Your going to have to drill your splitter depending on the amount of sprayer nozzles you want. I drilled 3 holes. More than enough to drown my IC.

Once you're done drilling your shroud, you can hook up the nozzles with the elbows and T's and have it ready. See pic below for diagram of how I hooked mines up:

The tricky part is to make sure you can get the nozzles to spray straight down, instead of out of the front of your hood scoop. On my first try, it sprayed my hood instead of my I/C. So I had to re-adust. The neat thing is that you can losen the splitter and kind of use it to bend the nozzles slightly downwards, then bolt it back up and it will naturally push the nozzles downwards towards the I/C. It may take a few tries.

Step 4 - Preparing your switch
Choose where you want your switch to be located (console or dash). You'll have to do some more custom cutting with your razor blade. It depends on which switch you choose. The switch I chose has a round end, so I just cut a small circle into the button location on my dash.

Step 5 - Wire/Hose Routing
Route your LOAD wire from your switch to the pump.
Route your power wire to the battery.
Route your grounds wires to grounding points.
Route your hose from the scoop to the pump.
You can use the snap ties to hold your hoses/wires together so that it doesn't flail all over the place.

To route under the carpet/molding is fairly easy because it's easy to lift up with just a little jerk/pull. You can't really mess anything up. It's easy to put back together.

To get to the engine bay, there is a small grommet right behind the clutch pedal that leads there. Just take this and cut a slit and a small hole in it for the hose and wires.

Here is how I routed the hose to the scoop:

Step 6 - Connecting your wires/hoses
For the switch:
-Connect the power wire to your in-line fuse.
-Then connect one side to the battery with your ring terminals.
-And then connect the other side to your switch with your quick-disconnects.
-You should already have the LOAD wire routed from the switch to the trunk. Connect these with quick disconnects.

-Connect the ground wire to a grounding point with a ring terminal (either negative side of battery or to a bolt that is grounded).

For the pump:
-You should already have the LOAD wire routed from the switch to the trunk. Just connect it to each device.
-Connect the negative wire to ground (I found a bolt in my trunk that was grounded).
-Connect the hose to pump.

Here is an animated picture of the pump+tank:

The great thing about connecting wires is, if it doesn't power on when you test it or if it shoots sparks and things start to burn, then you know you connected something wrong.

Here is a diagram of my routing and wiring of the whole system:

Step 7 - Test your system
Press the button. See results. Adjust anything as needed.

See animated test results below:

Final Thoughts
I know routing it in the trunk was kind of a hassle. I could have just hooked up the pump to my factory washer fluid tank and been done with it. Other people also like using the STi sprayer and STi switch. I chose the cheap route. To each his own. Have fun!

Feel free to PM me and ask questions. I'm not the most advanced mechanic or most techinically inclined, but I can try and help.
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