Persistant Blow of 20A Main Fuse

Those Fluke Fuses aren't exactly cheap either. I've been OK with mine at a steady 10AMP, but somewhere above then Poof it goes.
I remember your thread your post now, did you check that the rubber ring, at the head lamp bucket, where all of the wires come in is in place and hasn't cut into some insulation? There is 2 of these 1 on each side of the bucket.

Went through a good 12 fuses before I ran out working on it today. Unplugged all the lights. Fuse still went. Then things got kinda strange. I had the thing running for a while, the fuse hadn't blown for a good 6 or 7 minutes. I figured "ok. I'm gonna take this thing for a ride". As soon as I sat on the bike the fuse went. This got me thinking. I put a new fuse in and tapped the frame with a piece of wood, fuse went. I was able to reproduce this about five times. Then it stopped. Anyway, back at it tomorrow with more fuses, more meter, less stick.

"tapped the frame with a piece of wood, fuse went. I was able to reproduce this about five times."

Uhm Alex, wasn't once enough to inform you you have a short occurring under your seat pan due to your fat ass? :blink: :laugh: :laugh: :laugh:

Sounds as though your real close to finding your culprit... Once you do, yell out real loud.... Then beat the hell out of that short with your stick....

You'll feel much better... :woohoo:

BTW, not sure about the KZ650 harness runs but for my 900, harness is under the seat pan for the run to the rear tail/brake light assembly....

hmmm....

I hope against hope my fat ass is responsible for all of this.

Harness to all my back lights runs right under the seat pan. So, I unplugged it. Fuse still blew.

alexnelson wrote:

78 KZ650 D1

I started a thread about this a while back but haven't been able to work on things for a while. I figured I'd start a new thread because so much has changed since the first post.

My main 20A fuse blows as soon as my bike warms up. I fire up the bike and without touching it at all, the fuse will eventually go after about 2 minutes. If I replace the fuse immediately after that and try to start the bike again, the fuse will blow instantly. Sometimes it blows as soon as I turn the ignition key but this is only after the bike has warmed up.

Due to scorch marks and excessive heat (will burn your fingertips) around the connections to the reg/rec, I thought maybe I had a bad reg/rec. A couple people told me to unplug the reg/rec and see if the fuse still goes. So I did that, the fuse still went.

This leads me to believe there is a grounding problem elsewhere, though, I have searched high and low on this thing without any luck. I've opened up the controls and headlamp almost a dozen times, no exaggeration, and can't see anything.

Is there anyway to use a meter to track down something like this? I feel like I'm just shooting in the dark here.

I've never tried it but I'm sure it works, Take a 10 AMP circuit breaker and replace the fuse with it, bike on and circuit breaker kicking in and out use a magnetic compass to follow the wires it will point to the short. Was a trick I was tought in my electronics class in automotive collage at University of Northwestern Ohio.

Thanks a whole bunch, Kenny.

Now I've gotta dig around and fine my compass. :laugh:

Good Fortune!

do you have a new battery?

alexnelson wrote:

...It all started when I opened my headlamp to tighten the nut holding the left signal light to the headlamp housing. Now you're all thinking, "Well, your problem must be in there!" Maybe it is. But like I say, I've had then thing open so many darn times and can't see anything wrong....

According to wiring diagram for this model, the front blinkers also serve as running lights, always ON, and receiving voltage when ignition switch is ON.

Such continuous voltage is fed through the blue wires into the flashers (probably coming from a dual connector inside the headlight shell).

When tightening the nut, perhaps the blue wire was shorted against the flasher stalk.

If not already done, could disconnect the blue wire feeding left flasher from the connector inside the headlight shell.

And re-test.

Good Fortune!

Stator wires getting hot is a clue. Try taking off the seat and tank. Check hazard switch and relay under the tank up front of the bike and check all the wires along the backbone to the mess of wires going to reg, rect, etc. Have you messed with the hazard stuff? your tapping the frame on what side? left? It's got to be close to there. I just got done cutting the wire plug to the headlights and ignition to shorten them. (I don't have any wires going through the headlight) rewired all the tail, brake, turns, ignition, pretty much the whole nine. It was frustrating for hours and hours several diff nights. Now I'm to the point where I feel confident about the wiring I'm loving it. I'm wireman! I'm gonna do the WIREGEORGE MODD for my ignition as WELL. Gotta love those relays! Take note there are only so many wires that branch out of and from the plastic encasing the wires that run along the back bone. Check these, see where they go and unplug like you mean it! Blow some fuses man! Don't forget to look for burnt wires coming out of the encased bundle, like the bk and y ground wires. These all tie together at diff places. Did you know there are two sets of four wires each set going to one single wire inside the rubber wrapped around the head light plug (engine side of plug) isn't that just flat out amazing? SO, lets go over this again. Flash cards are painted bk&y bl br o r bk grn y s gry r&bk. :blink:

elfmagic17 wrote:

I've never tried it but I'm sure it works, Take a 10 AMP circuit breaker and replace the fuse with it, bike on and circuit breaker kicking in and out use a magnetic compass to follow the wires it will point to the short. Was a trick I was tought in my electronics class in automotive collage at University of Northwestern Ohio.

That sounds very interesting. I'll see about giving that a go.

kawsakiman wrote:

do you have a new battery?

The battery is near new and holds a good charge.

Patton wrote:

If not already done, could disconnect the blue wire feeding left flasher from the connector inside the headlight shell.

I ended up disconnecting the signal lights entirely but was still popping fuses.

nads.com wrote:

Check hazard switch and relay under the tank up front of the bike and check all the wires along the backbone to the mess of wires going to reg, rect, etc. Have you messed with the hazard stuff?

This is interesting. My hazards haven't worked for a while. Don't know why. Could be a bad relay. I unplugged the orange&green wires from the hazard relay and still popped fuse though.

nads.com wrote:

Don't forget to look for burnt wires coming out of the encased bundle, like the bk and y ground wires.

Oh I have scorch marks alright. Scorch on black&yellow and red&white to/from reg/rec. No surprise considering how hot my stator wires are getting. Will literally burn you.

Thanks for the feedback everyone. Much to do tomorrow.

Old Man Rock wrote:

Sounds as though your real close to finding your culprit... Once you do, yell out real loud.... Then beat the hell out of that short with your stick....

You'll feel much better... :woohoo:

Don't forget to skin it and make a belt out of it too.....

elfmagic17 wrote:

Is there anyway to use a meter to track down something like this? I feel like I'm just shooting in the dark here.

I've never tried it but I'm sure it works, Take a 10 AMP circuit breaker and replace the fuse with it, bike on and circuit breaker kicking in and out use a magnetic compass to follow the wires it will point to the short. Was a trick I was tought in my electronics class in automotive collage at University of Northwestern Ohio.[/quote]


There was a better thing we used on PC boards: there was some kind of sheet film to lay over wires that changed when it got warm. It was kind of like a mood ring for wires. If you can, replace your battery with a 12V power supply (battery trickle charger might work) so you are not feeding enough current into the system to fry things, just enough to get them warm to hot. Then locate what's getting the hottest.