I took the 7R (1991 ZX7R K Model) out for a ride last night that didn't go as planned. I went to a local gas station (about 2 miles from my house) and when I shut the bike off to fill it up the neutral light and the oil light stayed on when I pulled the key out of the ignition. After I filled it up the bike wouldn't start so I had to call the wife to bring the pick up and get me. I disconnected the battery to see if whatever it was would reset itself. That didn't work and as soon as I reconnected the battery the lights came back on.

Here's some photos from today where I was diagnosing the issue:

Notice the key is out and the lights are on:



After pulling the tank,tail and airbox I jiggled the wires in the photo and the lights went out:





So now I'm thinking melted wires somewhere, so I start digging into the harness. I've found nothing so far but I eliminated a few things. Namely the ignition switch and the kill switch. If you look in the picture they're disconnected and the lights are still on:



Now I have the battery charging and I'm digging into the manual to figure this out. Any ideas on the culprit?

 

Here's an interesting thing I just noticed. Now that the battery is charged I can start the bike but the ignition key is completely useless. It's not needed to start the bike and it won't shut it off. The kill switch and start button still work though.



This has me wondering if it may be the starter solenoid possibly malfunctioning.

 

All the safety switches still work (Clutch, sidestand and neutral) to prevent the starter from engaging when it shouldn't.

 

I pulled the starter relay out of my 93 ZX7R and swapped it into the 91 to find I still have the issue. I believed the problem to be the relay but this contradicts that idea.

I also removed the fuse box and it didn't help. See attached photo.



I tested the wires at the relay and found the white wire to be constantly energized.





I followed this and it splits into 3 legs. One goes to the fuse box (which I already eliminated). The second leg goes to the alternator ( Since this takes place with power off we can eliminate that).



Here it is at the fuse box:



Here's the second leg where it plugs into the alternator plug:



and the third leg terminates at the ignition switch which is unplugged. So I'm stumped at the moment.

 

I was thinking starter relay, fuel pump relay, ignition box, headlight relay and even started looking at a diode in the alternator as possibly being bad. None of those things were but I believe I found the culprit.

This is a picture I posted earlier showing the alternator connector:



Upon further review I found this:






The white wire melted into the brown wire and powered everything constantly. This is really odd because these wires have been together like this for the last 22 years with no issues. Now I have it figured out and I'm happy. I can ride my favorite bike this weekend.

 

Certainly can't criticize your diagnostic methods. Glad you shared your experience, as it shows a process of elimination rather than the other popular method of problem resolution....throwing your wallet at it. Happy trails.

 

Hey Mike, glad you found the problem. Looks like the white wire has been possibly re-installed? (It is partially twisted, but the brown wire is not?) Might also check the (white wire) idiot-connector spade inside the housing, just to make sure it's tight/right. Next question is: why did it melt? Double-check the amount of juice going thru there, just to be safe. Good post; nice trouble-shooting, man.

 

Thanks guys. I was scratching my head for awhile on this. Now I have to re-wrap the wire harness and close it all up. Jeff, I've owned this bike since April of 1994. It's still the original wire harness without any tampering. I have no idea why it melted and I did check voltages everywhere so I'll insulate it really well and keep an eye on it.
To be honest I'm at my weakest with electrical and electronic stuff but I hate getting my butt kicked by anything so I just buckled down and studied the wire diagram then went point by point until I figured it out. I'm not the fastest or the smartest but I refuse to have someone else do for me what I should be doing for myself. Have a great weekend everybody.

 

Awesome find.


That heavy kink with the white wire as well does not look good.

Thanks for the great troubleshoot lesson.

 

Hey friends, I hope anyone can chime in, I know it's an old thread. Can someone confirm if the white wire is supposed to constantly show voltage when the key is off? The white wire connects to the ignition switch, alternator, junction box and starter relay switch. Mine is constantly showing voltage and I want to know if this means I have a bad starter relay/solenoid. Thanks for all the help!