Rewiring headlight to pick up power from the battery

[Guest]

I would like to rewire the headlight on my 1980 GS400S so that it doesnt draw its power from the stator but rather from the battery.

It would have its own dedicated fuse.

Is there a tutorial on this somewhere?

I can do it on my own if you forget about the ignition switch and you have it live at all times. I would rather it be done properly and I just dont know how to run it so it will shut when the key comes off so to speak.

Any help is apreciated.

[cowboyup3371]

Why do you want the extra drain on the battery like that when it's designed to run the way it is for a reason?

[jfman]

I read on here that one of the flaws of the charging system is that the current goes to the headlight before the battery.

I ride my bike daily (about 250 kms a week) and I have noticed that the battery goes slowly down when the headlight is on and charges back up instantly when the headlight is off.

I want to do the stator rewire along with a new R/R and finaly I want to rewire the headlight.

IMO it should have its own fuse anyway. One fuse for the whole bike is not smart.

[cowboyup3371]

You guys are both confused.

I wasn't confused by how it works just confused on why he wants to do what he is asking for.

[Toadstool Food]

Jfman, there is indeed a weakness in the charging system of your 80's models. The rectifier is not up to the job unless the system is fully loaded. The headlight switch drops one phase of the stator when the light is off. This is probably sufficient for an un-moded bike, but if you are concerned about it you will want to replace the rectifier with a better unit. Simply rewiring the RR is only going to melt your stator. Old has provided the correct link, and you can read more detail in The Stator Pages section of the home page.

[robertbarr]

You might mean something like this. Scroll down for "H4 Single Headlight Relay Kits", even if you don't have an H4. You can construct your own version, if you wish, but these are really high-quality.

Its function is to bypass old crabby wiring and send juice directly from the battery to the headlight. Your headlight will function exactly as it does now, except it'll be adequately bright. I doubt it helps or hinders the charging any. Maybe since the headlight will be drawing a little more current it will keep the R/R a little happier.

I've used this kit with success, and it really helps to see where the frig I'm going at night.

[Toadstool Food]

It's not going to melt anything

Well "melt" is probably a stong word, but as Peter Huppertz said in Stator Papers I... "we were contemplating the molten coils of my stator"

You be the judge. The fact is if you bypass the 3rd phase cut out, any extra energy generated by the stator is dissipated through the coils of the stator (as heat) because the stock RR is not capable of dissipating the extra energy (as heat). That "may" ruin the stator over time, as Peter pointed out.

Both of the recomended RR fixes also eliminate the need for the cut out.

Toad