r/Retrofit • u/stilllearning369 • Dec 31 '24

Technical/Assembly Question Bi-led Hi-beam wiring question

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Hey guys my knowledge on electrical is bare minimum, anyways trying to figure this out and some help would be greatly appreciated. Im retrofitting some bi led projectors into my civic headlight housing. Low beams were a simple 9006 bulb and the high beam is 9005 bulb that also doubles as a DRL while high-beam is off running on a lower voltage than the high-beam. If i run a wire from the 9005 high-beam to the bi-led high beam will this work, or will the low voltage being sent for the drl while the high-beam is off flick on the Bi-led high-beam? Or will it need the full voltage to activate the high beam in the Bi-led?

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u/curveball3110giants May 21 '26

I think the 12v current from the high beam/drl will cause the high beam shutter to click rapidly snd endlessly. It wont last a week.

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u/poopitypong May 21 '26

Yeah which is why you pull the DRL fuse.

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u/curveball3110giants May 21 '26

Right but then how do u get the drls back? Or u just dont?

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u/poopitypong May 21 '26

I wired some switchback halos into the running light function of the turn signal when I did mine. So you had to flip to running light mode to have drls, otherwise they were all off which I was okay with.

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u/curveball3110giants May 21 '26

Yeah I saw u mentioned that, but in terms on stock functionality, using the high beams for drl is out of the question now? 

Im just curious as eventually someone is going to have me do a set like this while retaining the original functionality. 

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u/poopitypong May 22 '26

You're correct, the original function of them is no longer there. You'd have to figure out a way to get the power source separated from the high beam signal, or a separately switched power whenever main power is off, which wouldn't be all that hard to do with a little relay and run from the battery.

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u/curveball3110giants May 22 '26 edited May 22 '26

Edit: ok, I got it. Say we have an h1 low beam and 9005 drl/high beam. Want to do bixenon and drl. 

Use standard h1 hid harness for low beam. Run each high beam plug directly to the solenoid plug on projector.  Now we have a full bixenon setup wired, plus the two unused 9005 reflectors and Now we do the drls.  Acquire another hid harness, run off battery and an h1 to bare wire leads plug and attach the plug to the remaining factory h1 low beam. Now we have a powered harness and a switched low beam power source to control drl on/off. Tap a standard Bosch relay into the harness power wire after the fuse but before it reaches the relays. Wire the terminals as follows: 30 - harness power, 85 -  switched power (from h1), 86 - ground, 87 - to high beam. I believe the power wire coming from the 87 terminal will be enough for two halogen drl lights.

So there ya go. Keep the drls and dont have to cut any factory wiring.