Ignition short!

[jonathansgreene]

Important info in bold/underlined

It's been a while since I've posted here (so i lost my old account info) but this forum has essentially fixed my bike several times now.

bikes a 78 GS750 that has a new (used) engine, freshly rebuilt carbs, new intake orings, freshly resealed air box w/ cleaned filter and new electronic ignition.

After putting everything back together the bike ran absolutely fantastic for about a week, then after hitting a bump the bike shut off completely (no lights or anything)

After playing the hit a bump off switch game a few times now it doesnt want to start at all, the key will turn the bike on but as soon as I switch it from off to run it blows a fuse and everything cuts off again.

Clearly a short that has to be somewhere between the switch, coils, ignition and battery, correct? (I think thats all the wiring diagram included for that switch)

Just thought I'd see if you all agree with my diagnosis and if so where do you think the short most likely is?

The bike is a 30 minute drive from me currently so before I drive down I want a list of things to try. I need it running so I can go through the stator papers!

[rem3160]

I would check and see if any of the wires got pinched when you put the seat back on i had that happen once and the wire wore through and instant short.

[koolaid_kid]

Get your wiring diagram.
Follow the 12V from the battery to the switch. It will go through a connector first, make sure you follow the correct wire. Sometimes they change color at that connector.
That part is fine. Now, using the table that shows the connections for each switch settings (OFF, ON, PARK, etc) follow the 12V when the switch is in the ON position. The ON position usually makes multiple connections, and you will need to understand and follow each one. (At this point the starter is not yet in the equation, so ignore it.) Somewhere after the ignition switch but before the Start button is selected, you have a short.

[Riding Again]

In my neck of the woods (if south end) PM sent.

[kdo58]

My connection coming off the ign. switch was melted, I solder mine, it was in the headlight bucket.

[jonathansgreene]

Get your wiring diagram.
Follow the 12V from the battery to the switch. It will go through a connector first, make sure you follow the correct wire. Sometimes they change color at that connector.
That part is fine. Now, using the table that shows the connections for each switch settings (OFF, ON, PARK, etc) follow the 12V when the switch is in the ON position. The ON position usually makes multiple connections, and you will need to understand and follow each one. (At this point the starter is not yet in the equation, so ignore it.) Somewhere after the ignition switch but before the Start button is selected, you have a short.

The bike stays on through all settings on the ignition switch(key), its the run/off switch located near the thumb of the right handgrip that blows the fuse.

I believe that switch is only part of the starter circuit and ignition circuit, and is wired in series with the ignition switch(key) on the starter circuit so I doubt the short is there, which is why I assumed the ignition circuit(coils etc)

PM'd back Riding Again

EDIT: The keyed ignition switch is new, in trying to disassemble my old one, I snapped it in half..

[Riding Again]

We're meeting tomorrow evening as it's just a few miles away.

[koolaid_kid]

The bike stays on through all settings on the ignition switch(key), its the run/off switch located near the thumb of the right handgrip that blows the fuse.

I believe that switch is only part of the starter circuit and ignition circuit, and is wired in series with the ignition switch(key) on the starter circuit so I doubt the short is there, which is why I assumed the ignition circuit(coils etc)

PM'd back Riding Again

EDIT: The keyed ignition switch is new, in trying to disassemble my old one, I snapped it in half..

That is known as the Kill Switch. Its purpose is to allow or disallow the ignition circuit to be active. So yes, you need to track down the wire (it is usually orange with a white stripe). I have not worked on that year of bike, but I would expect it to go to the points next (just a guess).

[jonathansgreene]

Oh yes I knew that... I've been working on my jet ski a lot lately and its ignition/kill switch are kind of one in the same. I'll begin the search next time I'm at the bike, likely tomorrow. ill let you know what i find, thanks

[Riding Again]

Found a pinched wire under the gas tank. Now onto the carb rebuild and then the stator papers!