driving at night and BOOM! no lights!

Well, I haven't had a chance to really give 'er a good goin over. Been crazy busy with work and mid-term exam's this week at school. Post some findings in the next day or two.

Your system was different than this one. Due to the Suzuki design where the ignition switch has two sources of charging power, the MAIN fuse and the R/R line directly connected to the ignition switch (unfused) the power went back to the fuse block, where the ignition fuse was still good. Thus the ignition still operated and he made it home.
In your case, everything, ignition, lights, horn, etc. got its power through the single fuse. When the single fuse blew, you were done. Make sense?

Except that my pre-fuse-box wiring did not put a fuse between the R/R line and the ignition switch. In fact contrary to the service manual diagram (in color here) the red line went from the battery (+) to the fuse and then forked to the R/R and IGN switch. The diagram actually puts the fuse in position to isolate the R/R and NOT the battery, but that's not what existed in the actual layout, thankfully.

So blowing that fuse cuts off the battery (+), but not the R/R. If you ran the wires per that diagram, the reverse would be true. A blown fuse would cut off the R/R but not the battery. Indeed, absent some diodes, I can't see how one fuse could protect both the battery (+) and the R/R red wire, unless the R/R were connected directly to the battery (+) unfused.

So I am still perplexed.

Actually I agree with your reading of the diagram - since the main fuse only isolates the battery, the bike should run off the charging system.

In my experience, however, when my bike had the original One Fuse To Rule Them All system, the One True Fuse sat in the same position as the main fuse we are talking about here. When that fuse blew (and it did a couple times) the bike would immediately die.

Why would that be?

Your system was different than this one. Due to the Suzuki design where the ignition switch has two sources of charging power, the MAIN fuse and the R/R line directly connected to the ignition switch (unfused) the power went back to the fuse block, where the ignition fuse was still good. Thus the ignition still operated and he made it home.
In your case, everything, ignition, lights, horn, etc. got its power through the single fuse. When the single fuse blew, you were done. Make sense?

Thanks Redman and Mistercylinders and you too Koolaid Kid. I will have some time on Friday to sort out some of this. It seems that the "replace and shake" method might be the best idea. I will look around maybe take a pic or two and report my findings. You guys have been super helpful. Oh and Redman, I was not very clear with my statement. When the Kawi blew a fuse, it stalled out. However, when the Zuki blew the fuses I still made it home....redundant by now I suppose. Got to say a big thanks to those Suzuki engineers!! I got it home and in one piece.

....except from the charging system.

The charging system red wire ties into the main red wire inbetween the main fuse and the ignition switch.

If do not have the main fuse, what you dont have is a battery connected to the red wire that goes to ignition swtich, you still have the charging system connected to the red wire that goes to ignition switch.

So if bike is running and charging system functional, could pull the main fuse and the charging system is still suppling power (do keep up the rpms) to the ignition switch (and then to Head fuse, Ignition fuse and Signal fuse).
I have not actaully tried this, just looking at schematics.

.

Actually I agree with your reading of the diagram - since the main fuse only isolates the battery, the bike should run off the charging system.

In my experience, however, when my bike had the original One Fuse To Rule Them All system, the One True Fuse sat in the same position as the main fuse we are talking about here. When that fuse blew (and it did a couple times) the bike would immediately die.

Why would that be?

[Redman]

Yes I can tell you, the ignition and main are not tied together . .........

Ah ... we were saying the charging is tied into the Main.
More specifically, We were saying that the R/R output (charging system) is tied into the wire that goes from the Main fuse to the key swtich (sometimes called ignition swith, but also switches other power besides that what goes to ignition).

Main fuse power (red wire from main fuse, not red wire from battery to main fuse) goes to key switch and the R/R output ties (spliced) into that red wire along the way to the key switch.
Key switch turns on and puts power on Orange wire. Orange wire comes back to the fuse block and powers the Head fuse and the Ignition fuse and the Signal fuse.

......... My 1980 Kawi blew a main this summer because of a bad ground and the bike stalled out. I made it home running on no lights. ............

- I dont know how Kawi arrange the fusing as it relates to the charging system. Could be differetn than Zuki.
- IF blew main and bike stalled, I assume you replaced fuse before could get bike started again. With no main fuse, I doubt could push start it (or kick start) enough to get charging system to operate the ignition. Do not really know.
- I cant think of how a bad ground would blow a fuse. By bad ground I mean a wire that should be grounded was not grounded, to me, that is a bad ground, and would mean that a lot less current is flowing. It takes too much current to blow a fuse. Unless by "bad goround" you mean a wire that was suppose to have power on and not be grounded was somehow grounded, now that would definatly blow a fuse (that would be called a short circuit to ground, and what we are suggesting you need to look for with your present proiblem). But anyway, let not get too distracted with this.



ANyway, aside from all the above discussion. Back to looking for possible cause of blowing fuses.

......... I only had an hour to look at it last night and haven't found any Bare wires yet, ........

Since you say blowing Headlight fuse and also Signal fuse (and Main), that leads us to suspect multiple wires are damaged somewhere.

When looking for where wiring harness may have some bare power wires, that could "short to ground", think of two possibilitys:
- where rubbing against some surface and would wear over some area along the wiring harness.
- were rubbing acrost some edge, sideways, and wear into the harness in only a narrow little slit. Harder to notice.
In eiter case it may be easier to find by moving around the harness and see if blows fuse(s) to at least narrow down what section of the wiring harness; inside headlight shell, up by frame neck, or by the main frame under the tank, or back under seat by battery, or back near tail light ..... then look with eyeballs.

And, there is an other possible cause of multiple wires being damaged, other than from rubbing against something, . . . but lets not talk about that yet.
Tell us what you find.
But do tell us if you find a place or two where it looks like a wire has melted through the tape that covers the wiring harness, maybe the black/white wire.

Dave

If you cannot shake out the short, stick a bunch of those fuses in your toolkit/pocket, so you can swap them in should you blow one on the road.

I suspect it will be difficult to find, and may not actually be a physically bare wire. I base this assumption on the fact that a large bump popped another fuse. That tells me that it made momentary contact only, then went back to no contact.
I suggest using Dave's approach in post #13. Get a couple of boxes of fuses and replace the ones that blew. Turn the key on. If one or more blows, you have a dead short and can trace that down relatively easy.
If one does not blow, then follow the wiring harness down its path, rapping on the harness at periodic points until one blows, then you have localized the position.
I realize it will be a PITA, but you have an unusual situation on your hands.
Best of luck.

Yes I can tell you, the ignition and main are not tied together . My 1980 Kawi blew a main this summer because of a bad ground and the bike stalled out. I made it home running on no lights. just for clarification, I only had an hour to look at it last night and haven't found any Bare wires yet, but I can only assume that is the issue. Thanks for all your input.

[Redman]

That's true. Doesn't it Y into the red wire somewhere under the tank?....
....

yes, and I have wanted to find that point where the R/R output ties into the main red wire in the harness (but that is another discussion).


.

....except from the charging system.

The charging system red wire ties into the main red wire inbetween the main fuse and the ignition switch.

If do not have the main fuse, what you dont have is a battery connected to the red wire that goes to ignition swtich, you still have the charging system connected to the red wire that goes to ignition switch.

So if bike is running and charging system functional, could pull the main fuse and the charging system is still suppling power (do keep up the rpms) to the ignition switch (and then to Head fuse, Ignition fuse and Signal fuse).
I have not actaully tried this, just looking at schematics.

.

That's true. Doesn't it Y into the red wire somewhere under the tank?
Then it would go back to the fuse block to hit the other 3 fuses. 2 blew, but the ignition one stayed intact, thus powering the ignition system.
I actually downloaded and printed out his wiring diagram, but I did not have an enlarger to blow it up to readable size.

[Redman]

dfin,

I might suggest that you Put your general location in user profile (User CP).

Dave

.

[Redman]

dfin,

Your first description of loosing multiple decvices did sound like a goround problem.

First quick look in the fuse box revealed 3 of the 4 fuses blown. Main, headlight , and signals. The one that was OK.... Ignition fuse, thus why I made it home! Now to figure out why?

But now that you say multiple fuses have blow, that is more like a short circuit to ground on more than one circuit.

Go get a pack of 15 amp fuses (main) and a pack (or two) of 10 amp fuses.
(dont bother with those assortment packs, they have mostly ones you dont need, and not enough of what you do need.)

THe turn signal controller is in both the headlight fuse circuit and the signal fuse circuit. SO if looking for one device that coukld effect both fuses (and main fuse) you can suspect that. Try disconnecting it, replace fuses, and see if fuses hold when turn key on. If they do hold, try wingling around the main wiring harness (take off tank so can grab it better). Try wiggling especailly were the wiring harness goes around the frame neck an other places the harness is close to frame. Look for where the insullation may be worn away from wires or wiring harness.

I suspect more that someplace the wiring harness has rubbed against something and have multiple wires with insullation worn away.

Tell us what you find.

WHen you say blew fuse in the rain, I suspect the horns (they are powered all the time when key is on, the button completes the ground), but that is in the Signal circuit and would not effect the Head fuse. IF short to ground in a horn, it will blow fuse as soon as turn on key, which is the same as will happen with bare wire in harness shorted to ground (assuming it is touching ground at that time). But can easy disconnect the horns.

Again, I suspect someplace on wiring harness has insulation worn away and bare copper grounding to the frame somewhere.

.

.

[Redman]

S............ that means that it was still getting power, which should not be possible if MAIN is blown.
Clarification is required.

......
..............If you blew the main fuse, there should be no power to the bike at all. ...........

....except from the charging system.

The charging system red wire ties into the main red wire inbetween the main fuse and the ignition switch.

If do not have the main fuse, what you dont have is a battery connected to the red wire that goes to ignition swtich, you still have the charging system connected to the red wire that goes to ignition switch.

So if bike is running and charging system functional, could pull the main fuse and the charging system is still suppling power (do keep up the rpms) to the ignition switch (and then to Head fuse, Ignition fuse and Signal fuse).
I have not actaully tried this, just looking at schematics.

.

Had that happen, There was a moon out and the turn signals still worked. Very little traffic. I rode about 10 miles without a headlight. Just hit the turn signals when needed for a little extra saftey