Now…. Onto the installation. First off, I had several goals that I wanted to achieve in addition to just having a sprayer system:
1. I wanted it to function EXACTLY like the factory STI system
2. I wanted the tank low-level indicator to work, as the WRX gauge cluster does not have the low-level indicator (amber LED)
3. I wanted to have a “pump activation light” (green LED) for troubleshooting purposes, as well as to know when the pump has finished cycling, so I can press it again if need be. Pressing the button twice does not make it pump longer, you have to wait for it to finish cycling before you can spray again.
4. I wanted the switch to be close to the shifter, so my left hand never has to come off the steering wheel. The factory STI system switch is located to the left of the steering wheel, and requires you to take your right hand off the shifter to hold the wheel, and then take your left hand off the wheel to activate the switch…. And then return back to your normal driving position every time you want to spray. This is a poor design in my opinion, so I thought I’d fix it.
First things first… disconnect the battery
Passenger seat, rear seat, and door sills must come off
Interior trunk carpet removed
Remove the driver side lower dash to access the foglight wiring and fuse box. You need to vampire clip the following wires from the foglight harness (foglight harness is installed in ALL cars, regardless of whether or not foglights are installed (I don’t have foglights)
Red, Violet, Orange with white stripe, and black (I used a different ground from other electrical work, but you will need to find a black groundwire)
Above the fusebox, you’ll also find the yellow wire with the red stripe. Use heavier gauge wire when you vampire clip into this wire.
Using zip ties, route the wires down the center console and bring them up through these holes
Now, do the exact same thing through the other hole, under the passenger side carpet (4 wires, plus one large gauge wire (10 or 12)….. and then run all 5 wires down the side of the car, under the carpet, by the brake lines. Use lots of zip ties
Run them into the trunk. I found a nice place, just inboard from the RR strut tower. Just ziptie your wires to the factory harness.
This is what it looks like from inside the trunk
Back inside the car, your wires should be coming from both directions. You’ll install the switch to make the connection
Now you’ll need to run your tubing. I found this firewall grommet on the passenger side of the engine bay. One tiny slit with a razor, and it slid right through.
You’ll need to drop down the passenger side lower dash, and the glovebox. You can see where the tubing comes through
Install the check valve, route it through the hood to secure it, and use the “L” tubes to cleanly route the tubing up to the sprayer nozzle
Now route your tubing under the carpet, right along side the wiring
Route your tubing and wiring to the back of the car where the pump is. I took this picture with the trunk OPEN…. Make sure you route it OVER the trunk hinges, or you will likely destroy your work.
I took this picture with the trunk CLOSED. See what would have happened if we routed the wire below the trunk hinges?
Here’s what the inside of the trunk looked like after I wired everything up and ziptied everything
I had to fab up this bracket to secure the front of the tank (GHETTO!!!!)…. I didn’t know I required this part, but I’m on the hunt for the correct part now.
Trunk completed
Interior completed
When the level of water in the tank is low:
While the pump is activated (stays on 2-3 seconds only while pump is pumping)