DDM Tuning HID Install in my 2003 GT


Mar 12, 2018
Based on all the great input and feedback regarding the DDM tuning HID kits, I pulled the trigger and ordered a kit for my 2003 GT. I have owned this car since I was 18 (32 now) and plan to keep it as long as it rolls. As such, I like to add a mod to it each year. So, this year its HIDs!

What I ordered:
Ultra HID Kit 9007 55w 5500k w/ Highi/Low function + Single Relay Dual In / Dual Out HID Harness

Fogs: Since I have the roush body kit I use the H10 bulbs
DDM HID Kit H10 35W 5500K

For the install, I began my first laying everything out on my workbench so that I had a general idea of what went where.
One great thing about the DDM kit is that they made it super easier to identify what plug goes where by having different adapters/plugs for each wire.
This makes it so you cant plug in a wire to a place where it does not go.

bench 2.jpg

I started my install with the fogs (H10 black box)
The kit for the fogs is direct plug and play using the existing wire harness. These bulbs do not need to be ran to the battery or ground like the headlights.
I jacked up the car and slid underneath.
Remove the existing H10 bulb and disconnect from the wire harness.
Connect the new ballast to the existing wire harness and then wire the bulb to the ballast.
I added a piece of 3m double side tape to the rear of the ballast and then stuck it inside of the metal support behind the bumper.
Then I wrapped each connection with friction tape and tucked all my wires inside this area where I mounted the ballast.
Did the other side the same way. Super easy!


Now onto the headlights.
Start by removing the headlight housing by sliding up the two clips that hold it in place.
Disconnect and remove the existing 9007 bulb

DDM includes an blue adapter which you will connect to the plug that you removed the bulb from.
Wire the 3 wires from the DDM wire harness as follows:
With the flat side of the blue adapter pointing up
Blue wire = left slot
Brow wire = middle slot
White wire = right slot

I then plugged the blue adapter into the bulb plug and wrapped with friction tape.

The hardest part of this install was finding a suitable location for the ballast.
I decided to remove the battery to gain better access.

Here you can see where I mounted the ballast using zip ties. You wont be able to see it when everything is back in


Insert new hid bulb into the housing and run your bulb wires back through to the ballast.
I then wrapped in friction tape and then secured the plugs and black box on the far left side.

Next I connected my ground to an existing green ground screw near the headlight. You can see it at the top of this pic

I then ran my power wire behind my battery and to the accessory connection port on the batter.
I did need to change out the terminal on the power wire to a bigger terminal.

Then I checked to make sure they worked. Here you can really see the color difference

Now for the passenger side headlight.
I remove the plastic above the screws and ran by wire under it so it was out of sight.

Remove the headlight assembly and disconnect the existing 9007 bulb.
The plug that was plugged into the bulb is not used. I taped it up and tucked it under the headlight housing.

I then mounted my ballast under the fender using zip ties.

Then install the new HID bulb in the housing and run your wires back to the ballast and connect.
I then wrapped all my connections in friction tape and tucked them under the headlight housing so they would not rattle around.

Job done! it was much easier than I anticipated. Took me around an hour total


Overall I am super satisfied with the kit. The color looks so much cleaner than the stock bulbs.
My headlights match my fogs very well.
The HID bulbs work 10x better at night then the stock bulbs. I doubt I will ever really need to use the high beams.

Thanks again for everyone who recommended the DDM kit. I could not be happier!

Hopefully this write up helps someone with their install.
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