Need electrical guru advise

[Clerek]

I am putting the finishing touches on my project, and need a little advise on the electrical side of things...

I am wiring up the headlight (new h4...pretty bright!), with a totally custom wiring job, done by myself, and am running into problems trying to figure out where to get power to the headlight, and the taillight. I understand how they are SUPPOSED to be, but am a little confused. On the wiring diagram, it shows the yellow wire going into the dimmer relay and the blue wire goes to the RLU. If you do the RLU removal mod, then you are supposed to connect the blue/yellow wire to the blue/black wire. If you follow that wire then viola! you run into the left handlebar switch (LHS) that controls the headlight high and low. The other two wire you are supposed to connect for the RLU removal mod, is the yellow and the blue/green wire, which if you follow the wires the yellow branches off to the headlight for the high beam. I know the low beam is supposed to get it's power somehow, and I am thinking that it gets it from the yellow/blue wire.

That's the explaining, now here is the problem/question.

With the new wiring harness I no longer have anything that isn't ABSOLUTELY nessisary to run the bike. Therefore don't have the RLU, or the dimmer relay, or the speedo/tach cluster...nothing that "isn't needed to run the bike." Here is where the problem lies. Where do I get the power to run the headlight and tail light? I could just hotwire it from the battery, but that may be bad, and I would rather have the bike (generator) power the headlight. Can I just branch off the yellow wire from the generator, plug it into the 10a fuse, to the LHS (which wire though?) and then to the low beam (and somehow high beam), and then off to the running lights/taillight?

I understand the wiring I did, but am just looking for some outside opinions about wiring up my headlight/taillight/running lights...

Thanks all!

-Rick

wiring diagram...

[b.walker5]

No, I dont think you can. The genny produces AC and you need DC for your lights. The yellow wire might well be a part of the field coil DC circuit (I dont have it on my SG) but I doubt the circuit will take the current load of the lights. Do it the way the original wiring did it. Power the headlight direct from the battery, via a relay powered by one leg of the generator. That way you wont have to deal with the light being on while trying to start the bike. The tails lights can just be powered direct from the fuse block, through a switch or through the same relay as the headlight.

[Ivan]

In electrical, everything should be powered by the battery and the alternator replenishes the battery. It smoothes out the surges, and makes everything much easier to wire and deal with. It is also much easier to protect the circuit properly. I.E. the fuses need to be as close to the power source as possible. If you aren't sure where the power is coming from then its difficult to make sure you don't have un fused wires running around waiting to short out and cause fires.

FWIW, concerning the electrical system on these scoots, there isn't a whole lot that isn't necessary. You said you are removing the dimmer relay. Relays are there to handle load that switches can't, so you are asking for electrical troubles galore. Also the RLU is there for a reason as well, and defeating it's feature is probably not worth the "oh ****" moment when the low beam goes south at the wrong time. This is all IMHO, of course.

FWIW I at one time was ASE certified, and have taken the electrical training from the big three auto manufacturers and several custom upfitters. So, I do speak from some experiance and knowledge of electrical.

[bgrubb7]

In electrical, everything should be powered by the battery and the alternator replenishes the battery. It smoothes out the surges, and makes everything much easier to wire and deal with. It is also much easier to protect the circuit properly. I.E. the fuses need to be as close to the power source as possible.

Ya, you need some type of battery. Even if kickstarting and no starter. I see from an earlier post that you're building a hardtail chop, so I understand that space is at a minimum. You should be able to find a battery that is little smaller than stock, but still has enough amps to turn the beast over.

Here is a simplified wiring diagram that I found over on thechopperunderground forums. I'm planning something similar, but with a small fuseblock rather than inline fuses.

[Clerek]

Ya, you need some type of battery. Even if kickstarting and no starter. I see from an earlier post that you're building a hardtail chop, so I understand that space is at a minimum. You should be able to find a battery that is little smaller than stock, but still has enough amps to turn the beast over.

Here is a simplified wiring diagram that I found over on thechopperunderground forums. I'm planning something similar, but with a small fuseblock rather than inline fuses.

WOW! I really wish I had this diagram when I rewired my bike!

So with this diagram, the red wire IS supplying enough power back to the battery, from the rectifier? I know the three white wires go from the generator to the rectifier and that the rectifier regulates the power for the bike, but does it also recharge the battery? I thought I knew more about this, but I guess redesigning a whole new electrical system isn't taught until junior or senior year...Masters?

Should I put all those parts back on the bike then? I still have the RLU and the dimmer relay, I could just wire those onto the bike and go from there...This just peeves me, because it is running beautifully right now. I just don't have headlight or taillight wired into the bike. Any ideas on this?

Thanks guys, it really helps to brainstorm with other people on this!

-Rick

[Clerek]

Also I just noticed that on that wiring diagram, the subnote #2, says that these open wires are for the lighting that isn't shown on this...I'm starting to get some more ideas on this! I will report back later today, but in the meantime if anyone has any input towards this, that would be muchly appreciated!

-Rick

[DiverRay]

For the lights, just run a single 20A. fused wire from the battery. Use it to power the tail lights, and as was suggested use a relay to power the headlight, with the "power" wire from the same 20A. fuse. The #2, Blue wire from the ignition switch will switch the relay "on".
The relay has 4 connections, two are for the coil that activates it, and the other two transfer the energy once the relay has been switched. The Blue goes to one side of the coil, and the other side should go to ground. The power from the battery goes to one side of the contact, and the other side goes to the headlight. For low and high beams, you should use two relays, one for each. You CAN wire without relays, but you may find your headlight low/high switch getting HOT
HTH

[Clerek]

I fixed the battery problem! I called the battery place and exchanced the one I bought for one that was sealed. I mounted it on it's back, and am about to mount it to the bike. I made a pattern out of 1/16th sheet metal, and cut it out and am jb welding the corners. I will paint it flat black like the rest of the bike, and it being homemade adds to the look of the bike!

Now to figure out the headlight...

I understand what you said DriverRay, but am still confused as to which relay I should use. Should I use the RLU? or the Dimmer relay?

-Rick

[xs11bobber]

Maybe you should look at shops website. It may help you a little.

www.shopschops.blogspot.com

Click the sections that are pertaining to you. I think he even used stock harness, but he may have some useful information in there for you. Ask him questions, he always answers mine. HTH

[TopCatGr58]

Hey Clerek,

Again, I state I'm no electrical guru, but I can appreciate your minimalistic approach. Simplicity is also a nice goal. With that in mind, using the RLU seems a bit much. It's main purpose is to turn on the high beam at a lower power level IF your low beam burns out, and send a warning to you via the dash lights to let you know your low beam has burned out, without leaving you running "in the day time" without a headlight. At night you would quickly notice that your low beam has burned out and flick it to HIGH. The dimmer high beam of the RLU switching is to also help not blind the oncoming cars, but the heck with them!

The need for a relay to handle the high power/current draw that the headlights require is essential, but trying to wire in a latching relay from the charging circuit is more complexity...IMHO. I, too, would prefer to have an On/OFF switch for the headlights to assist in starting the bike without that extra drain.

I would however recommend using a gang type fuse block coming off a large power lead from the battery to power at least 2 separate fuse circuits, one for the headlights, and one for the tail lights. I can't recall if you are going to be using turn signals vs. hand signals? The OEM turn signal circuit alone uses a 20 amp fuse because of the draw of the bright 27 watt each turn signals, and the current flow needed in the flasher relay....IF you use a thermal flasher. Using LEDs and an electronic flasher can reduce the total amount of current draw for that circuit. The tail/brake lights use a 10 amp fuse alone. The headlights also use a 10 amp fuse, but that's for the headlights only. But using separate circuits allow for loss of tail lights or headlights without necessarily loosing both!

So...looks like you would need a RELAY and switch to provide power TO the headlight circuit being able to have it OFF when starting, and then a second/dimmer relay to switch the low/hi beams when you throw the low/hi switch. The tail lights could be wired with power when the key is turned on, since they don't draw that much power so a relay for it probably wouldn't be needed. Lots of options depending how complicated you want to make it!
Good Luck.
T.C.

[bikerphil]

my .02

I've been running both my bikes without a headlight relay or RLU for years now with no problems.

[Clerek]

Okay, thanks guys!

xs11bobber, I have checked out Chops site, but he is overseas right now, so my contacting him would be in vain. I did my hardtail EXACTLY like he did, and other various parts of his build have been very educating. Thanks for the tip though.

TC, I am not going to be using the turn signals (YET) as they are not currently required by law. I will be adding LED strips to the rear edge of the fender though later on. One of these http://www.radiantz.com/cart/startup.html if you watch the rotating picture, you can see one on the fender. It is a three part flexible led. The middle is the running/taillight, and the outer sides are the turn...Pretty slick looking! Anyways, can I use anything off the stock harness to help with these relays? I honestly don't care about the headlight being able to be turned on/off, and I am using the stock left hand switch. I am looking for something easy, that wouldn't require anything too complicated to implicate. I am using your fusebox, so I have extra spots for fuses.

bikerphil, how did you do that? Did you just hotwire the relay and then do the RLU removal mod?

Thanks again all!

-Rick

[bikerphil]

Clerek, for eliminating the headlight relay, unplug it, jump the red/yel and the blu/blk harness wires together. The headlight will now come on when the key is turned on.

As for the RLU bypass, it's described here...

http://www.xs11.com/forum/showthread.php?t=874

[Clerek]

Alright so, if I do both, and I am doing to rewiring from start to finish, then it would look something like this:



If I do the removal of the headlight relay first, then I would connect the blue/black wire with the red/yellow wire. Then when I am removing the RLU, I am supposed to connect the blue/black with the blue/yellow. BUT, what if I just skip out the blue black wire alltogether and connect it to the red/yellow wire down at the Right Hand Switch control?!? You are basically already connecting the blue/black to the red/yellow and then to the blue/yellow! That blue/black wire seems a little redundant. SO that is how the headlight get's it's power to the LHS...Then the next step in the removal of the RLU, is to connect the yellow wire to the blue/green wire, which just so happen to be two wires that both go into the LHS and control the high beam (?), or at least the yellow wire does.

So I am going to go wire it up like this, and if all goes well, then it should turn the light on when I turn the key on...I think!

Thanks,
-Rick

Let me know if you see any problems with this...

[Clerek]

So I ended up doing it a little different, but it worked! I hooked up the wires like I said in my previous posting with a slight modification. I hot wired the main power for the LHS to the brown main switch wire. I then ran it through a 20a fuse at the fuse box, and to the actual Left Hand Switch. It works really well, but as soon as I turn the key, the light turns on and gets HOT ! It is not going to work the way it is right now, but if someone has any helpful information as to how one would cool down an H4 bulb, that would be gravy...

-Rick