• Cut the red/violet wire which supplies power to the headlight washer pump.  
  • Solder (or butt connect) the pump power lead from the mister controller to the red/violet wire that leads back into the harness.
  • Cover the exposed red/violet wire from the blue connector; it will no longer be used.
  • Find a suitable switched +12V power source and connect the mister controller power wire. I used the 4th empty fuse slot (which also powers my Valentine One radar detector). 
  • The controller did not come with an inline fuse so I put a 10 amp fuse between the switched source and the controller.  The documentation states that the controller can supply pumps that draw up to 10 amps so I fused at the limit of the controller relay.
  • Note: not all cars have the 4th slot free.
  • Connect the controller ground to a suitable location.
  • My controller is currently in the glove compartment since I didn't want to mount it where it was hard to adjust.  Both harnesses run up close to the firewall over to the glove compartment without much trouble.  Eventually, I will mount it up under the dash on the passenger side.
  • Now, on to the plumbing part which is the easiest part of the whole project.
  • Assemble the spray nozzles as shown. 
  • Release the pain in the butt clamp on the washer supply line and disconnect the hose that goes to the headlight washer. Curse as the water begins to drain out of the washer tank getting you and all your tools wet.
  • Insert the nozzle (which you already assembled, right?).  Ahh, forgot to put the clamp on the line first didn't you? Pull out the nozzle, install clamp, insert nozzle.  Repeat for the other side.
  • I have not devised an elegant way to secure the mister nozzles so at the moment mine are crudely zip-tied to the upright for the fog light.  Looks cheesy, works great.
  • If you have fog lights on your car (I removed mine) you'll have to figure out how to get the nozzle and the fog light to play nice together... this is an avenue I didn't explore since I removed my lights in the interest of lower intercooler temperatures.  See my charge temperature testing here.
  • The right hand mister proved to be a bit of a problem since the existing hose is not quite long enough to get the nozzle directly in front of the intercooler like the left side.  My quick solution was to angle the nozzle and spray in the direction of the intercooler.  Thanks to the confines of the intake duct the water goes where it's supposed to and does its job.  Eventually, I will extend the line and mount the nozzle correctly.
  • To secure the nozzle I drilled 2 small holes in the duct and secured it with (yet another) zip tie. If you drill holes be careful not to drill into the A/C condenser that lives right behind the intercooler duct.
  • Reinstall the bumper grills.
  • Check the operation of everything per the guidelines supplied with the controller which is basically that you have 4 green lights when you power up and start the engine.  If not, recheck/diagnose.
  • Put everything else back together.


The controller does not offer any numeric feedback or markings to indicate where the injector duty cycle (called "fang" on the controller) or the temperature threshold are set.  The default setting on the controller was pretty close for fang and only required minor tweaking to suit my needs.  Temperature threshold calibration was a horse of a different color.

To fine tune the temperature threshold I eventually bought an indoor/outdoor thermometer ($20 at Lowes) and mounted the outdoor probe on the back of the intercooler right next to the controller sensor. The readout is mounted  inside the car where I can easily see it.  Without a temperature readout I found I set the temperature threshold way to low and consumed lots of water or too high and got no spray.  Trust me, get a thermometer and save yourself lots of hassle trying to tweak it by the seat of your pants. I spent a week trying to get mine right before I got the thermometer.  Plus, it's interesting to watch the temps while you drive... intercooler temperatures are not always what you'd expect.  

I have the temperature threshold set to trip when the intercooler temperature is about 25-30F above ambient.  The "fang" threshold is set to trigger when I call for more than about 3/4 throttle. The way the fang responds is I step on the throttle, boost comes up and right about 2,700 rpm the engine demands enough fuel and threshold is tripped. With these settings I find I can go for about 2 weeks of normal driving (2.5 tanks of fuel) before I need to refill with water.  

Intro | Install Part 1 | Install Part 2 | Testing | Monitor

Terms of Use Privacy Policy| Copyright © 1996-2012 by AudiWorld. All rights reserved.