Yam_Tech314's official build thread

[G_YamTech_314]

Here's the '76 and '78 diagrams. You're just gonna need to figure out which one to wire your bike up as, print that one out, and go through it wire by wire, checking continuity until everything's matched.

If you don't follow some sort of logical plan, you'll just go nuts.


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I printed both of them out. But I'm probably going to go nuts either way. The ignition switch is a three wire switch. The P.O all those years ago spliced in extra double female bullet connectors for the brown wire, lengthened the red wire, and added a red/yellow wire and an extra blue wire connector to the original blue wire coming from the iggy switch. Just might go nuts anyways.

 

[Kevin Werner]

I'm getting a measurement that is about 1VDC lower than Batt. Voltage.

I'm getting a measurement that is about 1VDC lower than Batt. Voltage.

If that reading is after the key/ignition switch, it is common to have dirty contacts in the switch. Cleaning them up is straight forward but a little fiddly. Disassemble over a clean surface, shoebox top or old pie tin.

 

[G_YamTech_314]

My right hand switch has all the wiring colors to match a 76 diagram.

The left hand switch has all the colors to match a 78 diagram. I need to basically pretend the wire colors on the switch are a lie, cross reference both diagrams to determine which wire does what, then connect them to their corresponding harness wire.

I'm in for a long ride.

 

[Jim]

I'm in for a long ride.

Yep.

 

[willis]

Interested in an unmolested 77 harness?

 

[G_YamTech_314]

I don't think it'd help me.

It's probably a me issue. As in: a skill issue. Electrical has always been my downfall. I can fix problems I can see. Not ones that I can't see.

The horn is the simplest thing on a bike and I can't get it to blow. Lol.

 

[G_YamTech_314]

I'm no doubt having issues with the bars being grounded. If I wirebthe horn with clips straight to the battery it'll blow. And it'll blow off I touch the front fender, the forks, the motor, etc. not when I touch the bars.

 

[G_YamTech_314]

If I use a jumper from positive post on battery to power side of horn, and boost my handlebar ground with a jumper straight to the battery, then plug my pink wire in, then the button works just fine... But if I use the harness to try and accomplish the same goal I get nowhere. Surely I'm having a hard time grounding my bars properly. But why.... And why do I also need a direct line to the battery on power side...? It's more than just the ground issue. It's both lol.

 

[Jim]

It's not unheard of for folk to take a ring terminal big enough and install it on one of the handlebar risers... then ground the other end to the frame. If you go that direction, make sure and scrape some paint off the bars where they clamp to the riser.

 

[G_YamTech_314]

It's not unheard of for folk to take a ring terminal big enough and install it on one of the handlebar risers... then ground the other end to the frame. If you go that direction, make sure and scrape some paint off the bars where they go under the riser.


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Where do they usually choose to put the other end of that wire? I'm definitely not opposed to it. I noticed when I tapped my lead to the brake line it also grounded out just fine. Perhaps that's not a good thing. I remember way back before I replaced the switches that I electrically melted the rubber off the front brake line somehow. Still a mystery to me...

 

[Jim]

Where do they usually choose to put the other end of that wire?

Under the tank where the coils are. There's several black ground wires that go there.
Although... anywhere on the frame where you can get to bare metal and there's a bolt or threaded hole will work.

 

[Wingedwheel]

It's probably a me issue. As in: a skill issue. Electrical has always been my downfall. I can fix problems I can see. Not ones that I can't see.

I’m thinking it might not hurt to do some continuity checks on your harness. Sometimes problems can be hidden where they aren’t obvious. That harness that @willis offered might be a consideration. Remember when reading the diagrams just take it one wire at a time, looking at the page as a whole can seem overwhelming.

 

[G_YamTech_314]

I’m thinking it might not hurt to do some continuity checks on your harness. Sometimes problems can be hidden where they aren’t obvious. That harness that @willis offered might be a consideration. Remember when reading the diagrams just take it one wire at a time, looking at the page as a whole can seem overwhelming.

I continuity tested each and every wire I tested today and they were all totally fine.

The harness was brand new when I installed it. There's no teeth marks or any scrapes or pinches in it whatsoever. I'm for sure making a stupid mistake somewhere. I get 12v to the horn but it's got a weak ground. Likely because of the way the bars are mounted. I'm gonna keep chipping away at it but it's gonna take awhile to figure it out.
Im using it as a good opportunity to fum le my way through electrical diagnostics. Can't learn if I don't force myself to.

 

[Kevin Werner]

Please treat this as a learning adventure. Your motivation is the XS650 you desire. There are steps to achieve this and each is a learning moment. I have been "learning" since late 2021. Remembering the issues I waded through brings a smile to my face. I developed, with forum help, two nice daily riders and learned a load of knowledge and understanding in the process.Do not forget your loved ones and family in the process. Cheers

 

[Raymond]

Adding an earth wire from the lower fork yoke to the frame - mine goes to the engine head mount - should be seen as a standard step. Otherwise, the way I picture it, all the electrics on the handlebar and instrument area are relying on electrons somehow finding their way through the ball bearings and grease in the head-stem. On another forum, a gentleman suggests that 99% of electrical problems are bad earths, and most often bad battery earth.

. . . Electrical has always been my downfall. I can fix problems I can see. Not ones that I can't see. . .

BTW, please forgive this digression, I have always been an electrical numpty - great word, Google it. But I junked the entire mess that was the PO hacked-about wiring and re-wired the bike to a simplified scheme of my own devising. I've now re-wired a couple of bikes, with just the things they need - no added complexity of self-cancelling indicators or light-checkers on any of that nonsense. I keep the diagram I draw, it shows the wires in the colours I've used, and there's no excuse now for not understanding the electrics. Every wire in there is one I put there, I know where it goes and what it does. Worth thinking about?

 

[G_YamTech_314]

Its been a long time... Life never stops. Time keeps passing by, and my poor XS650 lay incomplete beneath the awning of my rear porch where it has sat untouched and unloved for a better part of two years. I tried to briefly (half assed) wire up some LED signals, and a rear brake light/tail light combo. I failed. Ive since made it one of my 10 goals for 2025 to FINISH the damned bike or SELL it. I don't want to sell it. I'll be finishing it this year. Taking baby steps to get each and every little piece of this electrical shit figured out as I go. I have been reading up on LED signal systems for the majority of my evening, and I've finally narrowed it down to a set of rear shock relocation mounts, some low profile rear signals, and a "no load" signal relay with 3 posts on it and a separate ground wire. I'll be completely starting from scratch on the wiring so that I can fully comprehend and understand it. I just need this to be something I can ride and feel proud of. 2025 is the year for completion. No more bullshit.

 

[gggGary]

Give r hell!

 

[G_YamTech_314]

Give r hell!

liking the updated profile pic! I'm sure I've missed quite a bit.

 

[Raymond]

Great to see you're back, looking forward to you finishing the bike!