Rookie, needs help.

[tw8872]

I bought a '80 xs400 back in March and between work and school been trying to get it running. I've been really digging into these last couple of days and I now realize what kind of trouble I am into. I was told that the wiring harness just needed to be reinstalled and it would fire right up. I got it mostly hooked up except for lights and I see that a couple of things are missing. When I put the battery to it the starter starts turning, but no spark. There is no key or a place for any key and so I guess that the previous owner did some rigging. I dont really know where to go from here. Any help would be appreciated.

 

[drewpy]

download a manual off this site first and print off 3 copies.

1) for the toilet
2) for bedtime reading
3) for slack time at school

get to know what things look like and you'll soon get an idea of how things should look

 

[bcware]

I completely removed my harness once already and putting it back was not too difficult. Pretty much everything was color-coded and the harnesses only fit into a unique female end.

Since you don't know what has been done to the bike or if it was running before for certain there is always the possibility that the problem is not the harness.

Start from the basics and make no assumptions. Be suspect of everything and walk through the bike starting at the points. Are they opening and closing properly? Are the insulated washers in place correctly? (on my bike the PO put them back on wrong!) Use the manual to check the coils and rectifier. Since your harness has been chopped double check those new chopped bits. Did the guy solder or ghetto rig the connections by crimping them on? Electrical tape might be hiding something.

Other than that, most of the connections that could be hooked up wrong are probably in the headlight; everything outside the headlight is a harness save for the wires going from the coils to the points. The other misc bullet connections outside the headlight won't affect starting. In the headlight everything is color coded and unique. Mine also had an extra loose wire; the wiring diagram for my bike does not acknowledge the existence of this loose wire, but since I do not have an electric start it probably is just the same harness used on a bike that does have one.

 

[tw8872]

Thanks for the advice. I'll get to reading and trying to figure this out. I'll update yall when I do.

 

[tw8872]

Alright, started some digging and I found the starter switch in a box of parts. From looking at the wiring diagram the red battery cable is supposed to go to it then the starter motor. Should I try to reinstall it? There are two wires coming off of it, one ends up at a relay and the igniter unit, the other goes to the starter switch. But the starter switch isn't connected to anything. I cant hook up the battery and check to see what's getting power and whats not. So, any thoughts?

 

[hmusket]

I looked at the wiring diagram for your bike, what they call the starter switch is what most of us call the solenoid. Yes, you need to install this if you want to use the electric start. Here's some pictures that might help:
The first is a picture of the solenoid with the red/white and blue/white plug. Does yours have this? The other two show how the solenoid is set up on an xs650. Tomorrow if I have time before I go to work I'll take a picture of the setup on my '81 400, which should be similar to your bike.

 

[tw8872]

hmusket, Thanks for the pics. Mine has the two bolt ends on opposite corners on a square side and the two screws opposite each other in the other two corners. I would post a pic but dont know how. I was reading in the manual about testing it but don't know which are the "low-tension leads or high-tension terminal", and therefore I dont know which post gets the wire from the battery and which one goes to the starter motor. The blue/white cable is still attached but not the red white. Thanks for the help and another pic would be awesome.

 

[tw8872]

 

[hmusket]

A couple pictures I took this morning. Disconnected solenoid from wiring harness. First picture solenoid. Second picture wiring harness connection. Imagine a r/w wire on the empty solder joint on your solenoid. The heavy gauge red wire would connect to the terminal to right of the r/w wire in your picture, the short battery red wire would connect to the terminal to the left of the b/w wire in your picture. When connected to the wiring harness the white cloth coated wire connects to the red wire, and of course the b/w and r/w combo mate to the other connection. In the second picture you can also see the white, black and red connection, thats from the stator to the rectifier.

 

[tw8872]

Thanks, that helps alot. But to clarrify the white wire is coming off of the red wire from the battery cable? And does the black wire next to the tarp in your second pic just get grounded off at the hole?

 

[tw8872]

Just saw that the relay is gone. How is that going to change things? Didn't see anything about in the manuals.

 

[hmusket]

I hurried my post this morning because I had to get ready for work, so it might have been confusing. What you see as a white wire is actually a white cloth covered red wire. And what look like black wires next to the tarp are electrical tape wrapped wires. Last night member Jayel posted a wiring diagram in color that I know will be quite helpful. Here's the link: View attachment 4786

I assume the relay that you are talking about missing is headlight relay? You can work around that, I don't believe it will effect you're bike starting, only the lights turning on after you start.