There are probably a handful of similar walk-throughs for installing backup cameras, but I figured I'd put one together with a lot of detail. My goal is to make a novice DIY'er comfortable with adding a backup camera to their 4th Gen Legacy with factory Nav installed.
: If you have an aftermarket double din head unit, the steps are very similar except for the OEM Nav-specific Molex wiring harness. You'll also need to make sure the reverse signal (found in passenger kick panel, or just use the +12V reverse light power wire itself) is wired into the head unit.
: 3 hours (making cables & installing wire)
: $35 and a Legacy w/ Nav
- Rearview camera
- 4-pin Molex "Mini-fit Junior", dual row, 4 circuits, part number 39-01-2040
- (3) Molex female sockets, part number 39-00-0038 or similar crimp socket
- Mini-fit Junior crimping tool (or use soldering iron instead of crimp)
- Soldering iron or other technique for joining wires
- Wire stripper
- Heat shrink or electrical tape
- Zip ties
- Philips head and flat head screwdriver
- Needle nose pliers
- Female RCA jack (I cut apart an old cable I found)
You can find the Molex parts on Ebay for pretty cheap. Here is an example that will probably be a dead link pretty quick: http://www.ebay.com/itm/P4-4PIN-MALE...5d0&rmvSB=true
My camera choice
: There are dozens of cameras on the market. I wanted to try something relatively cheap with decent reviews, so I went with the Cosmic Optix camera for $28
. The cable lengths and a lot of specifics in this walk-through assume using the stuff that this one vendor provided. Your experience with different cameras will vary!
Here's what is inside the box. There is an RCA cable, Power cord with wire leads, and the camera with dangling RCA and power cord connector leads. Also shown in this picture is the handmade Molex Nav cable that allows an aftermarket backup camera to interface with the Subaru OEM Nav system. We'll dig into the details of the Molex cable a little later.
This is all of the cables connected together. I added a note on something I learned in hindsight. The power cord isn't quite long enough to reach my preferred +12V power source: the passenger side taillight reverse lights. We'll discuss that in depth later.
Here is a comparison of the Cosmic Optix $28 camera for my 3.0R with the Pioneer ND-BC5 $160 camera on my LGT. (Left side Cosmic Optix, right side Pioneer)
2) Harness Fabrication
You'll want to start off by looking for the connector and pinout on the back of the OEM Nav unit. SVXdc (the resident A/V guru) has a good summary post here: http://legacygt.com/forums/showthrea...html?p=2943792
Lesson Learned #1 - RCA Harness Length
: In the picture below, I made very short stubs out of the Molex connector. My harness in the picture worked OK for me, but I really could have used a few more inches of harness length. I recommend making this jumper 6-12" inches.
I used a crimper, soldering iron, and heat shrink tubes to make a really clean harness. You probably don't have a Molex Mini Fit Jr crimping tool, so you can just solder a wire directly onto the female Molex contact and bend in the crimp wings with pliers. I suspect you can buy a 4-pin Molex header with flying leads coming out of it, but I haven't looked.
Lesson Learned #2 - Power cable Length
: As I mentioned in the Intro section, my power harness was too short. Add 2' to it at this stage. It's a lot easier to work with the cable BEFORE you install it into the car!
Update: SVXdc has a good recommendation to make the Molex/RCA cable really sturdy. Check it out here: http://legacygt.com/forums/showpost....2&postcount=34
3) Installing the camera in the trunk
The carpet on the back of the trunk lid needs to be partially removed. There are a handful of plastic friction pegs and 2 rubber stopper nubs that need to be removed. I used a couple flathead screwdrivers to get them out a little bit, and then I used pliers to yank them out. The rubber stopper nubs take a lot of force, so go to town on them.
Time to remove the plastic license plate panel. Remove the two bolts under the license plate. These are the only metal hardware that hold the panel on. There are a dozen push pins that let go pretty easily.
Be slow and careful pulling off the plastic panel. If you are careless, you risk damaging the panel.
Once you get the plastic panel off, you need to remove the plastic black trim that holds the license plate lights. You do this by pushing it out from behind. Just feel around behind the trunk lid and you'll find a spot to push. The black trim piece is also held in by plastic push pins. It comes out pretty easy.
Now it's time to roughly position the camera. Use the gap in the black trim piece to get the cable through. It fits perfectly! I was pleased to see no drilling was required.
Use the included two-sided to mount the camera. Snap the trim pieces (black trim and license plate trim) into place.
Now we can run the backup camera's power and RCA video lead from the trunk lid into the trunk. Carefully zip tie the harnesses and run them down the passenger side trunk hinge. You'll have to remove the plastic trunk hinge cover, which is pretty self-explanatory. You'll quickly find that the power harness is too short to reach an appropriate power source! I used some butt crimps to add some cable length.
Pull off the carpet over the passenger tail light and run the power cable down there. I used a spade terminal onto the nut that holds the tail light in to get chassis ground. I butt spliced into the reverse bulbs positive lead (black wire w/ red line) to power the camera when the car goes in reverse. There is no need to power up the camera all the time.
4) Testing the setup!
Using an old credit card, wedge it under the Nav bezel. Work it around and try to get your fingers between the bezel and dash. Be gentle and you'll find pulling a certain way pops the bezel right off. It takes some experimenting, but it's pretty easy.
Once remove the bezel, remove the two philips head screws and gently pull out the Nav unit. On the back is the Molex connector receptacle. Plug your RCA custom-made harness into this and place the Nav back in.
Turn the key on and put the car in reverse. If all went well, your backup camera is on the screen! If not, review your work for mistakes.