XS400E Wiring Troubles S.O.S.

Hello all. I've been working on a little project for a while now (I will try to post pictures soon) and we've finally made it to the wiring harness and general wiring crap. So basically what i have going on is, the bike is put back together and the wires have all made their way back to their respectable homes. My headlight is functional, the dash lights up, but for some reason the start button doesn't work.

Some nights I cry myself to sleep.

I am really bad with wiring, I don't know if maybe the reason it wont turn over is because I don't have all of the previous attachments on? (front and rear blinkers, horn, rear brake light) also, the two grounds in the headlight are not connected to anything. Would any of this be the reason for the starter to not turn over? Keep in mind the tank is not on the bike or anything, i just wanted to test the starter before I move any further. If anybody has any bit of guidance for me it would be greatly appreciated. I am dying over here fellas.

When I took the bike apart, it started up perfectly with the electric start.

All the grounds need to be connected, especially if you are bad with wiring. The starter goes to ground through the handlebar switch.

To simply test things you could jump-start straight off the battery... but I wouldn't recommend it if you aren't 100% confident in your understanding of the wiring.

I'm wondering if there are maybe some open loops or something, maybe dirty connectors? There is a wire in my headlight that has a double connection and as far as I can see there is nothing that plugs into it. As far as I know there is nothing missing from the bike.
And it is a 1978 xs400

If you have a meter I would check your continuity through your switch first unhook the harness and touching both wires and pressing the button you should get a beep if it's good then check silinoid unplug the harness at silinoid and jump the two harnessed wires in (pic)one to ground other to positive and see if it responds if not bad silinoid bro

Damn if it runs into a safety relay that could also be a prob I straight wired a lot of my stuff and refused everything that needed fused so you need to download the manual from this site and trace back

Ok just connect a positive to one side and GROUND to the other side of the silinoid harness after unplugging it you should then see a contact and hear the plunger

NAPALMROLLER said:

If you have a meter I would check your continuity through your switch first unhook the harness and touching both wires and pressing the button you should get a beep if it's good then check silinoid unplug the harness at silinoid and jump the two harnessed wires in (pic)one to ground other to positive and see if it responds if not bad silinoid bro

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Is it fairly common for those solinoids do go bad, I mean it is 30 years old.

had the same issue with my xs850. It was because I had painted bars so the ground wasn't being completed. Like napalm said, check your grounds.

Yes, the handle bars are your ground for the starter button. It grounds to the left side light switch housing.

xschris said:

Yes, the handle bars are your ground for the starter button. It grounds to the left side light switch housing.

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So if I got new handlebars (which I did) should I strip the paint off of them so I can get that ground off the handlebar switch? Not fully strip the paint but just the spot I need, you know what I mean.

Yeah, strip it bare where the contact is on the starter switch. Or you can replace your starter switch with an aftermarket one and run a ground to the frame.

Yes, but both sides of the bars where each switch ( high beam/turn) and starter button are housed.

If you don't want to strip paint you could run a new ground wire from the headlight bucket to the handlebar controls. A ring terminal under one of the screws in the housing should take care of it.