1980 yamaha xs 400 hardtail chop

[fourdegreediablo]

Hey guy's I'm having some electrical issues see if anyone could point me in the right direction. This bike is a 80 yamaha xs400 with a 78 engine in it. I have it fired up and running and I gotta say it;s a blast ! My problem is that my bike charges ok when it has just the running and tag lights running but when I run the headlight it get dim and bike wants to die.Right now I'm in the process of cleaning up the electrical system so it's not ratty looking ! Anyhoo here's some pics I shot of my ride ...stretched 8inches drop seat hardtail with jockey shift and sits 3.5 inches off the ground.

 

[xschris]

I like the intake. How is the battery? It might be just as simple as that BUT with your wires they way they are now

 

[fourdegreediablo]

well the battery was with the bike to begin with and worked well. The only thing im concerned with is that maybe I left something out like elect components. I don't know
Would the headlight switch have something to.do.with it. I have my light wired straight to the high beam side

 

[Scorpio1963]

I could be possibly wrong but Im pretty sure running it without a dimmer switch isn't going cause any problems.I ran mine without it no problems when I was having trouble.
Best bet would be to look at the schematic of the wiring that's on the site.This was how I figured out how to run mine direct.Im also in the process of changing lights altogether to something that doesn't draw as much amps and is brighter with no dimmer.My new light is recantangerler but much smaller than say the light from a seca.
Also just curious why do you have your air filters running off to the side?

 

[xschris]

Where I live you need to have a high and low beam to pass an inspection.

 

[ratrodder69]

Did you do away with the head light relay? If so what did you do with the white wire? If that's hooked up to something it could drain the whole system?

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[fourdegreediablo]

for the time being I have the headlight running straight to main power and no relay. Could the relay have something to do with my problem ? And I put the carb tubes on cause I thought it would look cool so far they are staying on no problems .

 

[ratrodder69]

No that should be fine have you checked your charging system? And I know it a stupid question but if you are hooked straight to the high beam (or both high and low) are you sure you are using the correct ground terminal on the lamp?

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[weeza1989]

I ran my bike with no battery on it for a while(Had to hook a battery up for it to start but removed it once running). Headlight always stayed on even with no battery on it and it never killed the bike unless I stalled then I needed to find a power source to start it again haha. I would put a voltmeter on the battery. Should be about 12.3 volts with it off and 13-14.5 volts with it running, increasing in voltage with RPM. If its not in those parameters then you either have a bad batt., something is wrong with your charging system, or something is causing WAY too much draw. A good multimeter should help you out.

If you leave headlight disconnected, will it run indefinitely, or will it slowly drain the battery while running? You HAVE to have a voltage regulator and a rectifier for it to charge the battery. Pretty much everything else is optional.

 

[16VGTIDave]

You shouldn't run our bikes without the battery connected. It can damage the rectifier in the charging circuit.

 

[weeza1989]

Glad I have a battery on mine now then!

 

[fourdegreediablo]

Well I ran the bike and everything runs and sounds good ...well... with no lights lol! I swapped out the light with a aftermarket one to rule out the light and same thing happened blah. So I ran it again without the lights and hooked up a voltmeter and it read roughly 10.5 volts and did not go up the same as rpms ,so I'm not charging and if I am it's just enough to run the engine. I looked at my wiring and found that my wire connecter from the ignition side of the wiring harness has two wires that are not wired to anything a red/yellow striped wire and a dark blue wire. The reason I haven't wired them to anything is the wire schematic that I used from the xs 650 website didn't have it on the schematic. When it was running I checked the wires that weren't wire to anything and they both had no voltage output ...so either they are both negative or one is a signal wire to excite the alternator . Initially when I wired it up and ran a positive to the red wire I almost burnt the wire up so it cant be a input for positive. So all that being said ...now what, I am mind boggled !

 

[weeza1989]

Well, you cannot hook the charge wire directly to the battery. It must go through the voltage regulator and the rectifier. Think of the rectifier as a "one way valve" for the power. If the power output drops below the battery output, then it will keep the battery from "powering" the stator and will only let the battery charge once the power exceeds the voltage of the battery. My guess is that either it it fried or not wired in correctly(or at all).

 

[weeza1989]

Do you have both of these parts?

 

[fourdegreediablo]

the one on the right

 

[weeza1989]

You must have the one on the left for it to charge your battery.

 

[fourdegreediablo]

I'll go look it ran good before and I have all the wiring still.

 

[fourdegreediablo]

Is this the guy I'm looking for?

 

[fourdegreediablo]

I used another schematic for this setup but I think this is what I'm after. If so what is the block in between the regulator and the ground it comes off the regulator with a green wire and turns into a ground , looks that way to me anyway

 

[weeza1989]

I think the pictured box is for the blinkers.. not sure though. Type the part number into google and see what it pulls up.