Is this normal (stock wiring or...)?


XS400 Addict
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Spring Hill, TN
Bike is the 1981 XS400 Special II that I'm rebuilding with my daughter.

PO did make some changes to the harness, such as switching out the fuse box to inline blade-type fuses. So it stands to reason there may be other modifications. Everything seems present though.

We re-installed the harness yesterday and got as far as to turn the key and see lights on the neutral and oil indicators... so that's great:)

I've rewired a few bikes but also know that I am far from knowing everything.

Ran across two things that seem odd to me.

The first is at the starter solenoid. The wiring diagram indicates the two low-voltage wires that go to the solenoid as being red/white and blue/white, the blue/white coming from the start button. BUT... at the solenoid connector, the wires become switched; the red/white connects to the blue/white and vice-versa. The connector only connects in one orientation. See photo. I *think* at the end of the day, it doesn't matter because I'm just completing a circuit that engages the solenoid. But is this normal? Or should I reverse the wires in one side of the connector?

Ok next anomaly:
My right hand controls have 4 contacts in the connector, while the harness end of the connector only has three contacts. My diagram indicates three contacts, and the "extra" contact seems to be a ground from the switch that goes to nowhere. Normal? See photo; 4 female contacts in the control connector and three male contacts in the main harness connector.

Thanks! Excited to see this finally come together.
I just looked and my '81 Special II has the exact same right-hand switch wiring as yours (four pins in the switch side of the connector and only three pins in the harness side), so no issues there. It does look like there is an extra black ground wire coming from the switch gear that isn't used.

The start relay wires go to the coil of the relay, so are not polarity sensitive and will work as they are setup in your picture. The electrical OCD in me would have me pop the connectors out of one of the plugs and switch them because it would bug me any time I hit the starter button! The bike won't know the difference however.
@CaptChrome THANK YOU! Ha I was going to switch red/blue wires in one of the connectors for the same reason.

Ok one more follow-up since you have a reference bike at hand... We've been trying to figure out the factory routing for the wiring harness... as in how/where it snakes down the bike. Can't find a fit that seems to be right a far as all of the connectors being in good places.

Any chance of a photo or description? No rush!
Glad to help. As it happens, I just took the wiring harness off in the last few weeks and took some reference photos to remind me of where things were. I will get them off of the camera and post them here. Some of the wiring and components on my bike were "adrift" so-to-speak, but what I do have may help.

Have you looked at the cable/wire routing diagrams in the factory shop manual? Based on what I just removed, the diagrams look to be exactly how the wires were run. Between the diagrams and photos, you should be able to sleuth the routing out.
@CaptChrome I just realized I had the Haynes and not the FSM. I now see the harness routing diagrams... thanks for mentioning that. Looks like we were mostly correct but a few things need to shift a bit.

No rush on the photos but if you are able to post... that would be great.
While getting the photos organized I discovered that while spelunking around in the forum archive I had downloaded a few pictures of the cable/wire routing diagrams that are a bit better than the ones in the factory shop manual. These might be good to use as they are not missing bits that the manual scan missed. I wish I remembered where I got these to give some credit. My pictures will follow.

XS400 Cable Routing1.jpg XS400 Cable Routing2.jpg XS400 Cable Routing3.jpg
Here are some photos of what I had as I removed components. Hopefully they help, and if you have questions about what the view is of, let me know.

Harness above engine.JPG Harness battery box removed.JPG Harness fwd of battery.JPG Left bar switchgear plug.JPG Rear harness.jpg VoltReg plug and Rectifier cable under fusebox.JPG Wiring connectors under fuse box.JPG Wiring rear of battery.JPG Wiring under fuse box.JPG
Awesome. I have a few other pictures that mostly overlap with these, but if those might be helpful, I can certainly post them. Also, I know some of your mounting points were cut off of the frame, so if you want specific photos of any of how that stuff is arranged, I would be happy to help.
This is all we need; really helpful. We found a new frame with all of the factory bits and bobs, so all is well. Now what to do with the old frame... titled and everything.
You are in good shape then!

FYI - while looking at and testing my own wiring, it appears that there is another extra black ground wire coming from the left-hand switch gear that is unused. It has a lone female bullet connector that is bundled with the green, yellow and blue wires with male bullets from the headlight dimmer switch.