Low-Beam Headlight Wiring Harness?

Turns out I've opened a little bit of a can of worms here..... When I first bought my p5 a few years ago, I ended up needing new headlight bulbs. Looked up what type of bulb they take, bought two h7 bulbs, and replaced the driver side. All was well until I got to the passenger side and noticed it had an h4. Confused, I checked to see if for some reason Mazda has it wired as H7 driver side/ h4 passenger. Nope, H7 both sides. So my best guess was that some dumbass that owned the car before me wired it that was for some reason. Turns out that I'm the dumbass... Thinking someone had wired it in that way previously, I chopped off the wiring harness and wired in a h7 harness straight from O'reillys. Now, a few years later, with a little more wisdom I realized my mistake. What actually occurred is that someone must've lost the little black bulb socket that allows a h7 to go into that socket, and just stuck an h4 in there since it seems to fit. Now I know why my bulbs were always rattling around! The one side was missing part of the assembly and the other side just wasn't being installed correctly! Anyway, I went to the dealer and bought a replacement bulb socket (Again, the black connector that goes into the white bit), but obviously the side that I wired in the h7 wiring harness wont accept the black bulb connector. So my question is where can I find the wiring harness for a low beam with the white connector in the photo? Junk yard? Is it just a standard h4 harness and the black bit is basically a h4 to h7 converter? If anyone could give any suggestions, or a link to where to buy one I'd really appreciate it!

PS- Dealer says they can't provide it. They say Mazda only sells a full engine wiring harness.
Photos below

I think you should go find one at a junk yard..
I'll take two minutes to cut it off and two bucks to buy it. (cut a big length of wire with it)

The H4 has both high beam and low beam in one bulb.
The H7 has just the low beam with a separate high beam bulb.

The sedan uses a single bulb and our P5 uses two bulbs.
They're both Protgs and shared a lot of wiring.

I think you've got the right idea to hit up a junk yard. Appreciate the advice.

I may be able to tell you what socket it is, I'll try to remember to check tomorrow. I think a 9004 connector is what it is but I can check for sure tomorrow. I recently had to replace mine due to the same exact issue.