DIY wiring Homelink unit on 9th gen Accord (without using battery or splicing wires)
 

I searched high and low for a DIY on wiring a Homelink unit to the 9th gen, without having to use that little battery that collegehillshonda.com was selling. I also didn't want to splice into any existing connectors because A) I don't like doing that, and B) I don't want to void the bumper to bumper warranty on the vehicle in case one of the electronic components decides to take a dive on me.

Things you will need:

- Donor Homelink unit (I got mine off of a 2010 TSX)
- 25 ft at a minimum of 18-20 gauge stranded wire (I went with 18 gauge, anything thicker is just overkill)
- 2x ATM LP (Low profile) Add-A-Circuit kits
- 4x 5 amp ATM LP fuses
- Donor Homelink harness connector (I picked mine up from local LKQ junkyard for $0.99)
- 6 ft at a minimum of 1/4" wire loom or cable sleeve
- 1 ring terminal for the shared ground
- 4x butt connectors or a soldering iron and rosin core solder
- Electrical tap
- Phillips and flat head screwdrivers
- Zip ties

Optional but helpful:
- Multimeter
- Shrink tubing
- Trim and molding removal tools


Instead of posting pictures of how to remove the body panels in order to run the harness, I decided it was easier to attach the PDF from collegehillshonda on how to install an autodimming rear view mirror. The panels that need to be removed are the same, and the routing of the harness through the A-Pillar and headliner are the same as well.

https://www.pdf-archive.com/2017/08/05/daynightmirror/

This is my donor unit. Since it is a light tan color, I took it apart and painted the Homelink bezel black.
https://image.ibb.co/ib3gZv/s_l1600.jpg

Here is a look at the donor harness connector
https://image.ibb.co/bNMPnF/IMG_8581.jpg

This is unit with the connector plugged in.
- Green wire is Homelink +
- Black wire is Homelink -
- Grey wire is button lights +
- Orange wire is button lights -
https://image.ibb.co/cW2m1a/IMG_8578.jpg


I checked the current draw of the Homelink unit, so I would know what size fuse to use. The Homelink unit itself while pressing a button only draws 40 mA, while the lights for the buttons only draw 15 mA... Being that this is a low current device, I opted for 5 amp fuses. 2 amp fuses would work too, but I didn't have any on hand.
The general rule of a fuse is to protect the wiring and connectors in the event of a short. Since 22 gauge wire can handle up to 8 amps, you want to use a fuse with a higher rating than the device current draw but lower than the wire amp capacity. Which is why I opted for 5 amps.

In case the wiring on your donor Homelink unit is different than what I have pictured. You can check the polarity of the wires using a multimeter on the diode setting.
https://image.ibb.co/fSxKMa/IMG_8576.jpg

You can verify that your polarity is correct by testing it with a 9 volt battery
https://image.ibb.co/i6zzMa/IMG_8585.jpg

Next is the soldering (or crimping)... I trust solder more than butt connectors.
I staggered the cuts on the stock wire so I wouldn't have a fat wad in one place.
I used shrink tubing every few inches to keep wires together.
https://image.ibb.co/m4DR1a/IMG_8589.jpg
https://image.ibb.co/d7b1Zv/IMG_8590.jpg

For the wire that I used to extend the harness, I couldn't find grey or orange wire so I substituted yellow for orange and white for grey.
The length of the harness should be as follows (measured from the INSIDE part of the stock connector)
Length from connector to end of ground wires (black and orange) is 6'10"
Length from connector to END of Add-A-Circuit fuse holder (the plastic part) is 6'7" for the GREEN wire
Length from connector to END of Add-A-Circuit fuse holder (the plastic part) is 6'7" for the GREY wire


You need to connect or solder the two ground (ORANGE and BLACK from stock connector) wires together with 1 ring terminal
You also crimp or solder the GREEN wire to 1 Add-A-Circuit connector
You then crimp or solder the GREY wire to the 2nd Add-A-Circuit connector

Install 2x 5 amp fuses in EACH Add-A-Circuit connector
(if you are plugging them into an already used fuse location, install ONLY ONE 5 amp fuse on the portion where the red wire comes out of. The other slot should be used for the same fuse you removed to free the slot. So if it was 10 amp, use a 10 amp fuse in the other slot of the same connector!)
https://image.ibb.co/gRqjnF/IMG_8612.jpg

At this point I added both cable sleeves and wire loom to clean up the look of the harness
https://image.ibb.co/inhauv/IMG_8593.jpg
https://image.ibb.co/jTYgZv/IMG_8594.jpg

You should have the map light assembly removed if you've made it this far. So you need to remove the microphone and bezel from the stock map light assembly. You need to transfer the mic from your Accord to the donor homelink bezel. Then install the homelink bezel assembly into the stock maplight unit.
If you are struggling to remove the mic bezel, look on the backside and you'll see little locking tabs on the inside. Use a flathead screwdriver to push them down to remove the bezel.
https://image.ibb.co/kkpYga/IMG_8596.jpg
https://image.ibb.co/btBPnF/IMG_8598.jpg
https://image.ibb.co/fQogZv/IMG_8602.jpg

There is a pdf in the beginning of this tutorial in case you missed it. You need to run the newly made harness through the SAME location as those instructions state. Those are for an autodimming mirror but route them through the same location.

Once you have ran the new harness. Plug it into the newly assembled map light unit and reinstall the unit.
https://image.ibb.co/ds11Zv/IMG_8604.jpg
https://image.ibb.co/eUKzMa/IMG_8611.jpg

Now to connect the fuse connectors and the ground.
I connected the ground to this screw holding the panel to the metal panel under the OBD connector.
https://image.ibb.co/fadR1a/IMG_8607.jpg

There is a diagram on the kick panel that shows the number and purpose of each fuse.
On the 2014 Sport model, fuses 3,4,11,18, and 31 are free.

#31 is for vehicle with the push start feature which the 2014 Sport does not have.
https://image.ibb.co/kz0dEv/IMG_8553.jpg

Plug in the SHORTER of the two (the GREEN wire) Add-A-Circuit connector into slot number 31. (This slot has constant power) I like to be able to use Homelink when the car is off.
https://image.ibb.co/gyyR1a/IMG_8605.jpg

Now plug the LONGER of the two (the GREY wire) Add-A-Circuit connector into slot number 11. (This is switched power) You don't want the lights on the buttons always on, as it will drain your battery over time.
https://image.ibb.co/cVQjnF/IMG_8606.jpg

Now follow the instructions in the provided PDF at the top of the page, to reassemble your interior.

Reconnect battery, and test the homelink unit.

The lights on the buttons should turn on ONLY when the car is on.
The Homelink unit (the red flashing light inside the house logo) should function even with the key out of the ignition.
https://image.ibb.co/hJJtga/IMG_8609.jpg

Here is the link to the Homelink website in case you need help programming.
HomeLink

Let me know if you guys have any questions.