'79 XS650 - Wiring help

[Tom]

Hi all, new member here from Melbourne, Australia. I've just bought a '79 XS650 that's a US import with 15k miles on the clock. Overall, the bones are good but someone has been playing with the electrics and although I'm pretty competent with all things mechanical, I'm next to useless when it comes to electrics.

My question is that there's some cables that are disconnected from each other. As per the picture below, there's 4 wires (3 white, 1 black) in my hand which are connected to the rectifier. The others hanging to the right feed back into the main loom which I think go back to the generator by looking at a wiring diagram? If they are to be connected, how do I know which white wire goes with which? This is the only part that seems off to me, the rest is ok.

Thanks in advance!

 

[5twins]

For the 3 white rectifier wires running to the alternator, it doesn't matter which white connects to which white. Black is a ground of course but you should also have a red wire coming out of the rectifier. That is fed unswitched power from the battery, from the red wire that runs up to the key switch. I don't know why it's fed unswitched power like this, that's just the way they are.

 

[retiredgentleman]

As 5T says, you must have a red wire coming out of the rectifier, as well as the 3 whites and a black.
Its clear on the wiring diagram:

 

[Tom]

Thanks! There is a red wire from the rec that runs straight to the battery and has a built in fuse. Is that ok?

For the 3 white rectifier wires running to the alternator, it doesn't matter which white connects to which white. Black is a ground of course but you should also have a red wire coming out of the rectifier. That is fed unswitched power from the battery, from the red wire that runs up to the key switch. I don't know why it's fed unswitched power like this, that's just the way they are.

 

[nj1639]

It might look tidier if it followed the schematic, but as long as its fused.

 

[retiredgentleman]

Tom........................yes that will work. They must have a red wire going from the battery to the ignition switch.

 

[5twins]

I'm not sure if you removed it or it came to you this way, but all those wires you're showing usually went into matching multi-slot connector blocks, one on the harness and one on the rectifier. Then they plugged together.

 

[Tom]

Cheers 5twins. Yep it came to me in this state but those wires are now sitting in 6 pin connectors. Thanks for the help!

I'm not sure if you removed it or it came to you this way, but all those wires you're showing usually went into matching multi-slot connector blocks, one on the harness and one on the rectifier. Then they plugged together.

 

[DoubleE]

Tom, if these are the only wires that were disconnected,you might ask why. If you got the bike running, then the disconnected wires might point to a problem with the charging system. Could be that it was blowing fuses, or the rectifier, or simply not charging. If so, there is a good thread on the charging system in the Electrical subsection of the "Tech" tab:
http://www.xs650.com/threads/expanded-charging-system-guide-in-progress.10561/

Good luck with the new bike