Impreza Homelink Install

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Why?

It's not that having a Garage Door Clicker on my visor is an issue or anything. It's just that the 3 HomeLink buttons in my wifes van are just so much more ... well.... slick! I looked into the Universal HomeLink rear-view mirror kits, but at between $150 and $300, they were out of my price range. I thought to myself, how hard could it be to somehow retrofit a HomeLink button module into my Impreza? Turns out, it's pretty easy. And... pretty cheap. I spent under $40 including shipping for everything!

A few minutes on Google turned up someone who had already done just what I was planning.
C5 Homelink Install
Not only did this guy have instructions on how to rig it, he had detailed Photos too!!

Ok.. Nuff said, time to do my own HomeLink Retrofit!

Parts

Props to www.mouser.com for having the parts I ordered at my front door in a whopping 24 hours after I hit "Buy"!

All the parts needed for this

Tools

  • Soldering Iron
  • Alligator Clip Helper Tool
  • Drill & bits
  • Razor or Exacto Knife.
  • Screw Driver
  • Wire Stripper and Cutter
  • Voltage Tester
  • Needle Nose Plyers

Wiring Diagram

The Wiring Diagram

Installing The Buttons

The center section of the clear plastic has nothing behind it in the main housing. The 3 buttons I chose to use were very small, and a perfect size/fit for this spot. I had to cut away some of molded plastic behind the clear plastic to make enough room for the buttons.

The center square section that is cut away to make room


Measure and Drill the 3 button holes in my over-head map light. Then, just press in the 3 buttons. They are centered nicely left-to-right, but not centered front-to-back. This is because the plastic piece is snapped into place at a slight angle. With the button sticking through the back, I didn't want to risk them catching the main housing (there is enough room though). So, there are just ever so slightly closer to the top. In fact, the LED button is as close to the edge as possible.. Note I chose to use a dual Button/LED due to the small area I had to work with, I opted for this combination instead of adding a dedicated separate LED. I just didn't think there was enough room. The LED is not very bright, but it's more than visible enough for when it's needed. Which is really just for programming.

The 3 buttons pressed into place

Wiring the Buttons

Next, I soldered the 6 wires needed. Thanks to that writeup I found above, I learned that the 3 buttons used a common side. Which meant that for all 3 buttons, only 4 wires were needed. I cut off about 8" of the CAT5 wire for this. You won't need any more than that.

You can do any color combo you like, I went with:

  • Solid Blue -> LED Cathode(-) Identified with a small gray mark on the button.
  • Blue/White -> LED Anode(+) Opposite side pin from the Cathode
  • Sold Brown -> Button Common
  • Brown/White -> Button 1
  • Green/White -> Button 2
  • Sold Green -> Button 3
  • Orange Wires -> Trimmed Away.

The Brown Common wire I soldered to button #1, then ran 2 short shunts to buttons #2 and #3. The shunts are the heavier light-blue wire


6 of the 8 CAT5 wires soldered into place.

Wiring the Transmitter

Now for the really tricky part. I say tricky because you need a pretty steady hand, and a soldering iron with a fine enough tip. My iron worked, but it was bordering on being too big for this job. In the pic below, you'll see the Alligator Helper-Tool I used. This thing is CRITICAL!!! If you don't have one, GO BUY ONE!! I'm serious about this. The $8 it cost to buy one is way less than the frustration you'll experience trying to solder without it.

I used the remaining 12" of CAT5 cable to solder to the HomeLink module. It's a pretty good idea to keep the wire colors correct. In this photo, you can see where to solder the ends of CAT5. This is not my photo, it's from the C5 Corvette site I found.

This is the Photo provided by the C5 Guy.
It shows the soldering locations in detail.


If you follow the wire color pattern I already used for the buttons, you can easily see in this photo what wire does what.

  • Brown -> Common Button
  • Brown/White -> Button 1
  • Blue/White -> LED(+)
  • Blue -> LED(-)
  • Green/White -> Button 2
  • Green -> Button 3
Click the photo for a HUGE zoomed in version


Pinning the connector

This was again pretty tricky. The 6-pin connector I chose was quite small for a reason. I wanted to be sure it would fit through the opening. It fit with room to spare! In the parts list, I did indeed pick up "Crimp" style pins, but I crimped and soldered them. It was fine and tedious to do, but with that Helper tool, it was actually pretty easy. Just take your time, crimp and solder each wire end on BOTH sides. Then, when the pins all feel sold, precede to press them into the plug housings. Double check the wire-color matches on each plug end. You don't want to have to try and remove one of these pins once you've pressed it in. It's pretty hard to do.

One of the CAT5 ends being pinned

Here you can see the 2 pieces of CAT5 wired to but buttons and the Transmitter. With the 6-pin plug separating them.

The completed Buttons Wired to the Transmitter


You don't have to use one of these 6-pin plugs if you don't want to. I choose to do this so I could easily remove that clear plastic panel. But, in looking at it now, it's not really that important. With a 12-18" length of CAT5 going directly from buttons to transmitter, it would still work fine.

You could also get away with a RadioShack 6-pin Molex connector. It's much bigger than the 6-pin I used, but also much much easier to work with. I can't guarantee it'll fit though that square opening in the housing though.

Your call.


Tapping into 12v power

The HomeLink comes with a 12v power plug already. So, no need for me to get fancy here. I just extended the 2 wires by about 12", and soldered them directly to the power supply and ground. The over-head MAP housing is supplied with both constant (lights) and ignition switched (sun-roof) 12v power. It's up to you which you choose to go with. I opted for a dedicated constant 12v power to the transmitter.

Simply solder the 12v transmitter wire to the hot side of one of the map light switches. And solder the ground wire to the heavy black wire on the sunroof control switch. If you prefer to have the HomeLink wired to swtiched 12v, solder the 12v to the Red/White wire on the Sunroof Control Switch.

On the blue Map Light switch, the bottom (closer to the button) solder point is the constant 12v.

Red = 12v. Red/Blck = Ground

Installed

At this point, pretty much everything is wired and ready to be installed. You can see in this photo all the bits wired and taped up ready to go.

Ready to be installed


It took me all of 10 minutes to put it all back into my car. I shoved the HomeLink transmitter between the roof and the roof-pad above the drives side. I had to tape some foam around the transmitter to keep it from vibrating around up there.

Red = 12v. Red/Blck = Ground