First XS Project, 73' TX650

[westoftheocean]

Howdy folks!

This is my first XS, and I'm excited to get this bike back on the road. This guy I know bought this bike in good running condition, then promptly started a project he couldn't finish. He then sold it at a loss to a good friend of mine, who didn't have time to finish it either. Once it runs, I'm hoping to use on nice sunny days for my 2 mile commute and maybe some riding in the mountains on the weekends with the wifey.

So overall, she ran when parked, but while this dude was taking it apart, the original wiring harness got ruined. My buddy got a new harness from Mike's XS, and got it 50% installed. There are lots of extra wires, with no place to go because there no turn signals, and no instrument lights. That said, I don't really mind that. But I do want to get the harness sorted before things start going back together. I read a lot of the threads here in the tech section, and have set out to make my own wiring diagram based on one of the ones that Jayel made before I start modifying a perfectly good harness. Anyways, I thought i would post the wiring diagram here to see if any of you familiar with these bikes saw any issues with it or had any suggestions.

Wiring -

The bike-

Edit: Image quality

 

[5twins]

Your wiring diagram is too small to really see everything, but from what I can see, all that looks amiss is the combined rectifier/regulator. Your model uses a separate regulator and a separate rectifier. There are aftermarket combined units available but I would never buy one, they're too expensive. Instead, those components can be upgraded much cheaper using a rectifier from the electronics industry and an auto regulator.

 

[westoftheocean]

Sorry about the image size. Ill try again.

Sorry about that. Not used to the forum yet... I know, weak sauce.

As I was looking at this, a question did come to mind, should there be a fuse in line between the ignition and starter solenoid?

 

[westoftheocean]

As for the Rectifier/Regulator, my buddy bought one for the bike, also from Mike's XS. When he started installing the harness he found the wires to the Rectifier were cut. First dude didn't think it was important. Thats the joy of working on someone else's project.

 

[5twins]

No, usually the main 20 amp fuse is all that protects the starter solenoid and starter. Originally, your model only had that one main 20 amp fuse. The extra fuses you've drawn in were added in '78 to the Special models. The Standard models continued to use just the one main fuse. You can add those extra fuses in if you like but it's going to take some wiring mods to your harness if it is a '73 harness. It will only have a spot for the one fuse now.

There were two versions of the charging systems used on these bikes. They are very similar except for in the way the brushes are wired. The early version used up until '79 grounded the inner brush full time and the outer brush was fed power by the regulator to turn the alternator on and off. The '80-on system wired the brushes kind of the opposite. The inner brush was fed switched power (any time the key was on) from the harness and the outer brush was fed the ground by the regulator. That means 2 different types of regulators were used, a ground switching and a power switching type. You need the type that matches the way your brushes are wired.

So, you're going to need to figure out which way your brushes are wired, then determine if that combined reg/rec unit your buddy got is a proper match. They make them both ways, with a ground switching or a power switching regulator.

 

[westoftheocean]

Ok that makes sense. As for the fuses, I'm trying to keep it as simple as possible. There is only the one 20A fuse in the harness currently, in that location, and if I don't need to, I wont add any more fuses.

Now back to the garage to find out if the reg/rec is right or not. It is this one, https://www.mikesxs.net/yamaha-xs650-solid-state-rectifier-regulator-70-79.html

 

[5twins]

OK, that reg/rec unit should be the right one if your brushes are still wired as they were originally. This is what they should look like. The 3 screws that mount the inner brush ground it to the alternator casting. The outer brush mounts with only 1 screw and that mount is isolated from the alternator casting by the Bakelite brush holder .....

 

[westoftheocean]

Wow. Super helpful info. Thanks.

Im happy to say it has not been modified.

Now its time to go get some splices and heat shrink!

 

[willis]

I recommend you check out vintageconnections.com and get some factory style bullet connectors for your harness. Quality stuff and works great!

 

[5twins]

One more thing - the wiring for your reg/rec unit in your diagram is not right. That's the way the '80 and later systems are wired. You don't want the brown switched power wire running to one of your brushes, just into the reg/rec unit. The green wire should run to the outer brush (regulated power from the regulator) and a black ground wire should run to the inner brush.

 

[650Skull]

I'm not the electrical guy but from what i have found out is if you wire your mikes combined Reg/rect as per the wiring diagram as above it will be wrong.........the above diagram is the wiring for the 80-84 Factory TCI charging system,

Your wiring at the stator should have the green wire as regulating power and a black wire as ground..........on the coupling from the Stator to the Reg/Rect the green goes to green and the brown regulating power wire enters the Reg/rect from the loom coupling and comes out on the green to the Brushes..............

Read the links in this thread
http://www.xs650.com/threads/wiring-in-a-70-79-combined-reg-rect-to-a-points-model-xs650.52339/