After scouring various forums for hours and coming up with dead links and broken images, I've decided to have a go with a forum post and appeal to any of the knowledgeable blokes still floating around.

The problem:

• I would like to wire up an Australian WRX (H4 low/high) to a Japanese STI halogen projector (H1 low/ HB3 high).

The goal:

• Create a harness that allows for STI operation: Low beam = H1, High beam = H1 + HB3.

This is my last shot at trying to DIY this before throwing in the towel and trying potentially buying a harness. I'm happy to provide information or pictures to anyone who reckons they might be able to help.

 

https://www.scoobynet.com/lighting-a...eadlights.html

 

Hi Don,

Thanks for the reply. That thread was actually one of the ones I had run into.

I am still unsure about what is meant about one of the wires in the main loom side needing to be grounded separately. If I'm able to get you the pin colours for my car, are you able to explain more about what needs to be done?

 

The wiring diagrams shown in the link are from the MY01 UK/European/Aus workshop manual so the wire colour codes should be good.
However it's possible that the JDM colour coding could be different.

EDIT:
Just re-read the thread header

This attachment should help with wiring colour codes etc.

 

Hi Don,

Thank you so much. We had a go making our own wiring and were messing around with relays and the like.

I gotta say I was a bit thick and didn't read through the thread properly. I thought that the wiring would have made it so that the high beams lit up on their own without the lows; my mistake. The thread actually described it perfectly. I had the pigtails from the car side of the STI so I was able to just splice them into my home made harness.

Everything is all wired up now and works brilliantly.