aaroncarver Posted April 18, 2011 Share Posted April 18, 2011 Hey there. I'm Aaron Carver. Motorcycle newbie. Yamahaclub newbie. Milwaukee Native and resident. Proud owner of a 1979 Yamaha xs400. I used to ride a Honda Ruckus--A fun bike with not enough pep. Thanks to everyone for all the information on this great site. I've left some posts elsewhere on this site but I didn't know about forum etiquette so here I am to introduce myself properly...and ask a question I'm fixing up a 1979 yamaha xs400 and the first place I started was the wiring. I pulled the tape of the wiring harness and discovered that it had "modified" by the previous owner. Many circuits were crossed and there were insulation cracks and bad spliceds etc. So I figured I'd return the bike to stock condition--which meant completely rebuilding the harness. So I clipped all the plugs and taped them to my kitchen table in the order they appear on the wiring diagram in my manual. Then I threw away all the old wiring. Then I spent three days memorizing the wiring diagram. Yesterday I spent 14 hours wiring circuit by circuit, plug by plug, component by component. It was a daunting and mind bending task, but when 12:30 am rolled around I had finished everything but the Ground, which I measured and cut and labeled ahead of time. (I chose to wait till the end to install the Ground because of the way the ground attaches to every circuit--It would have made following the wiring diagram much much harder.) Everything went smoothly, albeit excruciatingly methodical and plodding. I need to adjust some of the wiring lengths, but that shouldn't be a problem. I only have one problem and I hope someone here can be of aid. The headlight cutout relay has a yellow wire with a red stripe that travels to a Fuse. From the other end of that Fuse, the yellow/red wire travels to the right handlebar switch (electric start button and kill switch) assembly, where it fits into a clip. BUT there the wire dead-ends. JUST STOPS. And according to the wiring diagram that is exactly how it is "supposed" to be. It seems that it should've gone to the electric start button, but it most certainly does not. Can anybody explain this to me? Can somebody look in their right handlebar plug and tell me if their yellow/red wiring is attached to anything at all? I'm truly stumped. Aaron (I'm posting this at xs400.com too) Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 18, 2011 Moderator Share Posted April 18, 2011 Greetings Aaron Drewpy is our XS expert, personally I have no idea what it is Link to comment Share on other sites More sharing options...
aaroncarver Posted April 18, 2011 Author Share Posted April 18, 2011 (edited) here's what I'm talking about: http://www.flickr.com/photos/61668060@N05/5631318268/ Edited April 18, 2011 by drewpy extension can't be used, so made a linky Link to comment Share on other sites More sharing options...
Moderator drewpy Posted April 18, 2011 Moderator Share Posted April 18, 2011 from what I can gather, the headlamp relay is for when you initally start the bike up (headlamp = running lights in the US) you obviously don't want the headlamp on when the starter is drawing all the amps it can! the relay is activiated by a feed from the rectifier which power only gets there through the alternator. (The alternator only works when the engine is running!) I think the engine cut out switch would also cuts the relay power (thus the headlamp goes out too) I don't have a US spec bike so can't take a picture It make have been cut or not used in your instance! Drewps Link to comment Share on other sites More sharing options...
aaroncarver Posted April 18, 2011 Author Share Posted April 18, 2011 Hey Drewpy. thx. It's just confusing to me why that headlight cutout appears to have it's own fuse and then dead-ends (not completing a circuit). Look at the flickr image I posted: According to the wire diagram (identical to the one in my manual) , 4 wires enter the harness clip and only three emerge. That's why I don't believe my bike has been altered. Having an entire circuit/fuse for one single wire that doesn't connect to anything seems (as described by the factory wiring diagram) is odd, don't you agree? There is no logic behind a wire starting in a Relay going through a fuse (without connecting to anything) and then dead-ending. Why put a fuse on a dead end? Link to comment Share on other sites More sharing options...
NE0 Posted April 18, 2011 Share Posted April 18, 2011 Hi Aaron and welcome, I'm sure this is not as uncommon as it appears.... Bikes and cars are all manufactured for different markets. A european bike will likely have a european wiring loom installed, but local variations to indicators and switches will be added to depending on its final destination. I'm sure the US market is similar. It's likely that your bike has a US loom and it would have been suitable for either US or canada etc. yes? If the wire ends in the plug then another plug with different wires connected could be plugged in to complete the bike. You say the diagram shows the wire and is supposed to be like that, but have you checked the wiring diagram for other countries? I bet somewhere you'll find the wire is used. It's easier for Yamaha to fit one loom than have several variants. In terms of japanese efficiency would they have installed the loom and removed the fuse if it wasn't going to be used later, or simply install the common loom and then install the next loom on the next bike and so on, regardless of its final destination? my feeling is its just one of those production issues and nothing more. After all, my car has all the complete wiring for cruise control, but the clutch and brake switches are missing, even though it has the fuse. Link to comment Share on other sites More sharing options...
aaroncarver Posted April 18, 2011 Author Share Posted April 18, 2011 Hey Ne0 okay, I've seen that before too: empty wires etc. for other features etc. But, what about the fact that the wire in question has its own fuse and seems to be completely its own circuit? Certainly Japanese efficiency would stop short of including an entirely unused circuit, correct? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted April 18, 2011 Moderator Share Posted April 18, 2011 Hey Drewpy. thx. It's just confusing to me why that headlight cutout appears to have it's own fuse and then dead-ends (not completing a circuit). Look at the flickr image I posted: According to the wire diagram (identical to the one in my manual) , 4 wires enter the harness clip and only three emerge. That's why I don't believe my bike has been altered. Having an entire circuit/fuse for one single wire that doesn't connect to anything seems (as described by the factory wiring diagram) is odd, don't you agree? There is no logic behind a wire starting in a Relay going through a fuse (without connecting to anything) and then dead-ending. Why put a fuse on a dead end? As far as I can see, its the right hand wire which goes to no-where, and not sure where the tail end goes! BTW do you have a starter motor fitted? Link to comment Share on other sites More sharing options...
aaroncarver Posted April 18, 2011 Author Share Posted April 18, 2011 drewpy Yep. I have a electric start and it worked quite well. (I have a feeling it weakened my battery, though...) I'm not sure what you mean about the other stuff. It's plain: the wire traces from the headlight cutout>>>>to a 10 amp fuse>>>>> to the start button/kill switch assembly plug. And goes no further. And it's quite clear from the wiring diagram that is was designed this way. It's confusing and I'm not sure that any answer will mean anything. Let me ask you this: If I cut out the e-start can I just tape off the wires? The reason I'm studying into this is because I want to get rid of the e-start/kill switch assembly from the right handlebar (for aesthetic reasons) and put a kill switch elsewhere. This of course leads me to wonder where I should put the mystery yellow/red wire with a fuse attached...Oh bother. Link to comment Share on other sites More sharing options...
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