I didn't really have time for a full detailed DIY, and this really isn't that complicated, but here are the most important things I'm gonna share with you on how I did mine. Some of them may sound like an overkill, but I did that because I have another project in the works, and I needed to have the extra juice available in the trunk:
Ran a 12awg wire from battery to trunk lid area and put a 20A fuse on that wire near the battery side. (If you try to connect HID ballasts directly to the reverse lights circuit wires, you'll blow a fuse.)
Installed HID ballasts in the trunk lid area. Again, I used unique ballasts, but if you don't get the whole kit and want just ballasts, you can search ebay for "replacement ballast" and "hid ballast connector" and you can get something like on the below images:
Then you can cut off the blue connectors and connect these wires as explained below in the terminal 30 connection of the relay.
Or you can get slim ballasts like these, so you can minimize the weight in the trunk:
Then you don't need the extra connectors, because as you see there are already input wires there. You'd just have to cut off the black plug.
Used 2 SPDT automotive relays (easily found in RadioShack) to power up the ballasts.
1 relay for each ballast. I used 1 for each just as a precaution, because of the specific ballasts I'm using, and because I have quite a few spare relays anyway. But I'm sure you'd be fine with using just one relay for both ballasts. You can also use SPST relay if you find one (because SPDT are just more popular), because you really don't need a dual throw relay. You're not gonna be using terminal 87a at all.
Connect terminals of the relay as follow:
- 87: the voltage wire you ran from the battery.
- 30: the input positive wire of your ballasts (the negative input wire of the ballasts should be grounded to chassis.
- 85: ground to chassis.
- 86: positive input wire from the reverse light circuit - one of the green wires that go to the reverse light bulb.
Remove inner tails and remove reverse bulb sockets. You may be able to find a kit with HID bulbs that are plug'n'play for 7440 bulb socket, I don't know, I didn't check, but if you plan to use D2S (or D2R or D2C) bulbs like I did, keep reading below.
The D2S bulb collar is slightly larger than the opening for the 7440 bulb in the tail, but not by much. I used a dremel to sand off about 1mm off the perimeter of the opening, so the D2S bulb goes in smoothly. There are also 2 little raised marks on the upper side of the opening, which I lightly cut off with a knife to make sure the bulb collar sits flash with the socket of the opening. Then I used a tiny screw from a HDD to screw in where the notch is in the bulb collar, so that the screw is sitting in the socket of the opening, but it's head is right in the notch of the bulb collar. This prevents the bulb from twisting around. The last thing is to ensure the bulb doesn't fall out. I found a way to hold the bulb in place by bending some hard wire, but it may be easier just to use a hot glue (which I'm gonna add the next time I take the tails out).
To connect D2S bulbs to the ballasts, I used cables similar to these:
Just search for "D2S connectors" on ebay and you'll have plenty of choices.