Easy JDM headlight wiring instructions - Honda Prelude Forum

Si4WS · 07-20-2002, 05:43 AM

I did this a few weeks ago and it still works so I thought I should post it up.

Basically I just wired the lights in the stock formation:
Factory Low beam positive lead to H4 positive lead
Factory ground lead to H4 ground lead
Same procedure for the high beams but run them to the JDM H1.

(optional) Then I just wired in a jumper wire from the factory positive high beam lead to the H4 high beam plug.
The H1 bulbs are used as a secondary high beam of sorts.

When I turn on my low beams the outside bulbs come on, when I turn on the high beams the second filament in the H4 bulb comes on along with the H1 bulb so I have super bright high beams. You can skip the last step and just run the factory high beam positive lead to the H4 high beam lead.

Sorry about the small image: ImageStation

I have a larger image to email upon request

brendon2k · 07-20-2002, 02:11 PM

Not bad. I still need to adjust minel. My low beams are very weak and the high beams seem equivalent to my old low beams. Did you guys notice those gear things on the back of the lights. I am figuring they can be used to adjust the direction of the beam.

Si4WS · 07-20-2002, 10:16 PM

Quote:

Originally posted by brendon2k
Not bad. I still need to adjust minel. My low beams are very weak and the high beams seem equivalent to my old low beams. Did you guys notice those gear things on the back of the lights. I am figuring they can be used to adjust the direction of the beam.

Yes they do adjust the position of the bulb. I have mine working better then stock now.

TheGreatOne · 07-21-2002, 12:43 AM

I have to re-wire mine...

This other guy I know has it wired so that the inner bulb acts as a fog light when the outer (regular low beam) is on..so all 4 are on..

This way seems easier though so I'll do this...do u have daytime running lights when u wire it like this?

Si4WS · 07-21-2002, 12:52 AM

No daytime running lights.

quickprelude · 07-16-2003, 10:44 PM

Si4WS, are you still running yours this way? any problems come about? i have mine wired in stock formation right now without the extra wire going to the H4 for the second high beam. please let me know....this is something i may want to try. thanks.

Si4WS · 07-17-2003, 07:20 AM

Quote:

Originally posted by quickprelude
Si4WS, are you still running yours this way? any problems come about? i have mine wired in stock formation right now without the extra wire going to the H4 for the second high beam. please let me know....this is something i may want to try. thanks.

Yes I am still running them like this with no problems thus far, it's been over a year now.

munscher · 07-17-2003, 07:43 AM

The whole idea of installing a relay inline is to avoid having both the low beam filament and high beam filament of the H4 energized at the same time. From my understanding it shortens the bulb life and greatly increases the risk of blowing the bulb and overheating.

I have my H4 wired to use both low and high beam with stock controls and a separate switch for the H1.

Just a heads up, but if you've had no problems then all the better for you.

quickprelude · 07-17-2003, 08:21 AM

so you can turn your inside lights (h1) on seperately from the outside lights (h4)? and the one filament on the h4 works as the low beam and the other works as the high beam? do you use the h1 as a driving light then? dont people high beam you all the time?

i just wired mine positive for positive and negative for negative from the usdm harness to the jdm harness. my high beams are the h1s and my low beams are the h4s. will i encounter any problems this way?

munscher · 07-17-2003, 08:34 AM

Quote:

Originally posted by quickprelude
so you can turn your inside lights (h1) on seperately from the outside lights (h4)? and the one filament on the h4 works as the low beam and the other works as the high beam? do you use the h1 as a driving light then? dont people high beam you all the time?

i just wired mine positive for positive and negative for negative from the usdm harness to the jdm harness. my high beams are the h1s and my low beams are the h4s. will i encounter any problems this way?

No, you're perfectly fine... and thats the easiest way to wire them.

The JDM prelude harnesses only have 2 leads on them (since they only use one filament from the H4 exactly as you have them set up). So what i did was get H4 harnesses from a civic so that i could wire up both the low and high filaments of the H4 (with the help of a relay for reasons i stated above) and ran an extra switch for the H1 bulb.

So driving down the road with my lights on, click the stock bright bar towards me and now my brights are on... reach over and push the H1 switch and now I have my brights AND my H1 bulbs on. The H1s are brighter than my H4 brights, together its pretty damn bright. I need better H4 bulbs though, nokya arctic whites suck.

quickprelude · 07-17-2003, 08:39 AM

Quote:

Originally posted by munscher

No, you're perfectly fine... and thats the easiest way to wire them.

The JDM prelude harnesses only have 2 leads on them (since they only use one filament from the H4 exactly as you have them set up). So what i did was get H4 harnesses from a civic so that i could wire up both the low and high filaments of the H4 (with the help of a relay for reasons i stated above) and ran an extra switch for the H1 bulb.

So driving down the road with my lights on, click the stock bright bar towards me and now my brights are on... reach over and push the H1 switch and now I have my brights AND my H1 bulbs on. The H1s are brighter than my H4 brights, together its pretty damn bright. I need better H4 bulbs though, nokya arctic whites suck.

thanks for clearing that up....it seems the more i read on the wiring, the more i get confused....lol. so the way the jdm h4 harness is setup....is the high beam or low beam filament being utilized as the low beam? couldnt i switch that to have a brighter low beam?

munscher · 07-17-2003, 09:12 AM

im not sure if the JDM harnesses use the low or high beam, i didnt pay much attention to it...

i know i've heard people say it both ways... but it seems to me if they used the high beam filament that they would be shining in peoples eyes everynight, so the low beam filament makes more sense to me.

quickprelude · 07-17-2003, 10:04 AM

Quote:

Originally posted by munscher
im not sure if the JDM harnesses use the low or high beam, i didnt pay much attention to it...

i know i've heard people say it both ways... but it seems to me if they used the high beam filament that they would be shining in peoples eyes everynight, so the low beam filament makes more sense to me.

if i check, is it the top post on the h4 for the low beam? or the left?

munscher · 07-17-2003, 10:28 AM

according to the diagram at the top of this page, the top post is low beam

Prelude_92 · 07-14-2005, 08:54 AM

is the diagram listed above displayed with the pins facing you or away??

rayslude · 07-14-2005, 09:39 AM

www.suvlights.com sells a plug and play harness that include relays in the wiring and also connects to your battery for extra power

Cashis · 07-14-2005, 11:43 AM

I ran both filaments on my H4 bulb for a couple of months before my aftermarket harness melted on the driver side. The passenger side is still running fine after a year or so. I guess it is a hit or miss when you run both filaments.

KB798 · 07-14-2005, 07:12 PM

Quote:

Originally Posted by Prelude_92

is the diagram listed above displayed with the pins facing you or away??

When I installed my JDM headlights, I interpreted this diagram as the pins facing me.

TruNinja619 · 07-14-2005, 08:40 PM

the wiring is pretty straight forward... just match each wire together....

Prelude_92 · 07-22-2005, 05:02 PM

what brand of bulbs do you guys have?