Headlight Rewire

[Guest Pete McCrary]

As most of you may or may not know, on 6th Gen VFR's, the lower headlights are the low beams although they are dual element H4 type bulbs. The high beams are H7 bulbs. The lower H4 type of bulbs only have two wires running to them, hence the high beam does not work when you flip the high beam switch on. The lower headlights just stay on low beam.

Several years ago (probably before the great crash) someone had written up how to rewire the headlights so that the high beam filament of the lower H4's came on in conjunction with the H7's when you switched to high beam.

Does anyone remember that post or the details?

Describing this situation, do any of you electrical wizards know what would have to be done to make this work in lieu of finding the old post?

[Darth Bling]

That was 767Fixer's mod. And that post is long gone. I haven't seen it in years.

It's actually pretty simple to do I have a hard copy of the post at home somewhere. I'll post it back up here tonight...

[Guest]

That was 767Fixer's mod. And that post is long gone. I haven't seen it in years.

It's actually pretty simple to do I have a hard copy of the post at home somewhere. I'll post it back up here tonight...

It was in fixers profile, but that is gone. I saw it somtime this year. Darth if you have a copy of this I would love for you to post it. I really want to do this.

[Guest]

Guys I would be forever grateful if y'all could find it. It seems like such a waste to have 4 lights on a sport bike and not get the full benefit of them.

[winaje]

If the old info can't be found, give me a couple of days and I'll do a write up on the system I have set up. It's similar to Fixer's mod, with a few changes. I have 2 lights on low beam, with an isolator switch so that I can turn the lights off if I have to turn the ignition on for a while without starting the bike. I have run 2x4mm fused power feeds direct from the battery, and 1x4mm earth return from the headlights to the battery. Light output is significantly improved, and all load is removed from the loom etc.

[Guest]

If the old info can't be found, give me a couple of days and I'll do a write up on the system I have set up. It's similar to Fixer's mod, with a few changes. I have 2 lights on low beam, with an isolator switch so that I can turn the lights off if I have to turn the ignition on for a while without starting the bike. I have run 2x4mm fused power feeds direct from the battery, and 1x4mm earth return from the headlights to the battery. Light output is significantly improved, and all load is removed from the loom etc.

Thanks Win. I like the sound of your setup.

[Guest]

Had a guy named "Keeena" on VFRWorld.com post up the reply to my same query over there.

Thanks a bunch Keeena.

[Darth Bling]

Can't find my copy of the thread, must of thrown it away.

Anyway, I drew up a schematic of how to wire your relays and headlights. This should do it. In the original thread, 767Fixer used a 5-pole relay that he got from a BMW dealership to replace the high-beam relay. But, you should be able to use your OEM relay just fine.

Basically, when the high-beam relay closes, power is delivered to the H7 bulbs and to the high-beam filament of the H4 bulbs. But, to keep the wattage down (and so you don't burn up your H4 bulbs by running both high and low filaments), you wire the low-beam relay so it's grounded through the high-beam power wires. That way, the low-beam filament is closed during normal operation, but as soon as the high-beam relay closes, the low beam relay loses it's ground and opens, thus turning off the low-beams.

[Guest]

Darth you are the man! Thanks. Can't wait to play with this setup! :goofy:

[jimmer]

Can't find my copy of the thread, must of thrown it away.

Anyway, I drew up a schematic of how to wire your relays and headlights. This should do it. In the original thread, 767Fixer used a 5-pole relay that he got from a BMW dealership to replace the high-beam relay. But, you should be able to use your OEM relay just fine.

Basically, when the high-beam relay closes, power is delivered to the H7 bulbs and to the high-beam filament of the H4 bulbs. But, to keep the wattage down (and so you don't burn up your H4 bulbs by running both high and low filaments), you wire the low-beam relay so it's grounded through the high-beam power wires. That way, the low-beam filament is closed during normal operation, but as soon as the high-beam relay closes, the low beam relay loses it's ground and opens, thus turning off the low-beams.

With the Low-beam relay energized, don't you create a series - parallel circuit? If you have 12 volts to the coil, and then you drop 0.5 volts across it, that leaves 11.5 volts. That 11.5 volts parallels to each high beam filament and then the current goes to ground. The low beam contact will conduct the current through the low beam fillament any time the low-beam relay is energized. Or am I just tired?

Drank a beer and looked again. Low beam selection will illuminate all 3 fillaments, as well as put more current through the LB coil than it would ever handle in the stock configuration.

[Darth Bling]

With the Low-beam relay energized, don't you create a series - parallel circuit? If you have 12 volts to the coil, and then you drop 0.5 volts across it, that leaves 11.5 volts. That 11.5 volts parallels to each high beam filament and then the current goes to ground. The low beam contact will conduct the current through the low beam fillament any time the low-beam relay is energized. Or am I just tired?

Drank a beer and looked again. Low beam selection will illuminate all 3 fillaments, as well as put more current through the LB coil than it would ever handle in the stock configuration.

Hmm, I gave it more thought and I remember that Fixer replaced one of the relays with a 5-pole relay (another thread on VFRD prompted this recollection). Anyway, this is how I would wire everything up:

I'd forget my earlier wiring diagram and do it this way. Replace the highbeam relay with an SPDT relay and reroute the power for the low-beams through this new relay.

[Guest]

Thanks Darth.

[Guest]

Can't find my copy of the thread, must of thrown it away.

Anyway, I drew up a schematic of how to wire your relays and headlights. This should do it. In the original thread, 767Fixer used a 5-pole relay that he got from a BMW dealership to replace the high-beam relay. But, you should be able to use your OEM relay just fine.

Basically, when the high-beam relay closes, power is delivered to the H7 bulbs and to the high-beam filament of the H4 bulbs. But, to keep the wattage down (and so you don't burn up your H4 bulbs by running both high and low filaments), you wire the low-beam relay so it's grounded through the high-beam power wires. That way, the low-beam filament is closed during normal operation, but as soon as the high-beam relay closes, the low beam relay loses it's ground and opens, thus turning off the low-beams.

With the Low-beam relay energized, don't you create a series - parallel circuit? If you have 12 volts to the coil, and then you drop 0.5 volts across it, that leaves 11.5 volts. That 11.5 volts parallels to each high beam filament and then the current goes to ground. The low beam contact will conduct the current through the low beam fillament any time the low-beam relay is energized. Or am I just tired?

Drank a beer and looked again. Low beam selection will illuminate all 3 fillaments, as well as put more current through the LB coil than it would ever handle in the stock configuration.

I haven't mapped this out, but it sounds a lot like the rewire I did on my Acerbis headlight to swap the low/high and have both on for the high beam. I used a couple rectifier diodes from Radio Shack (or Circuit City now I think) and the stock relays worked fine.

[Guest]

Not to dig up an old thread here, but I'm planning on doing this to my H4's because I'm getting a set of LED H4's that I want to utilize the High Beam on.

The SPDT 5 pin Relay. Do you only need 1?

Also, how far back do you have to strip the wiring harness, a foot or more?

Thanks!