[solved] Constant fuse blowing

[R1stu]

OK. SO I have just completed an engine swap on my ST1100 due to a water pump failure.

I tested the engine when it went in, and was running, along with the lights, horn and indicators etc.

Now Ive started to put the rest of the bike back together. I rebuilt the brakes, and noticed that the brake lights were not working.

I then looked at the wiring diagram, and saw the indicators are on the same circut. I tested these and nothing.

Upon closer inspection the fuse had blown.

I replaced the fuse and it blew again, as soon as I turned on the igntion.

Now I have unplugged all of the connections from the loom apart from the ignition barrell and the battery for testing. and it still shorts.

IF I put a bulb across the white/green fuse point to ground it lights. if I put between the fuse pins it lights (not sure if done correct but was told to try a bulb if stays lit then there a short)

If I place my multi meter on audio mode I get continutiy on all the end points of the wire.

I also get a contact between the light blue, and blue connectinos on the plug to the left switch gear (Indicators I think)

Any Ideas how I find where its shorting to ground without removing the entire loom and un taping it?


quick video

https://www.youtube.com/watch?time_continue=1&v=HU2piYuq0s4&embeds_euri=https%3A%2F%2Fwww.st-owners.com%2F&feature=emb_logo
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Carbon closet tart! https://www.bikepics.com/members/r6stuk/02r6/
Stolen bike. 2000 R1: https://www.bikepics.com/members/r6stuk/00r1/
Current bike 1991 Honda ST1100 Pan European, 1986 Honda cb350sg (Finished)

[Nobby the Bastard]

If you know the resistance of the wire and the change in current from in to short you could calculate the distance but this isn't really practicable.

Your best bet is to look at the loom and see if it's chafing anywhere.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[stinkwheel]

Systematic approach. That green/white only goes to three places. I'd put your bulb back in in place of the fuse. As you say, when it's lit, your short is still there.

So the wire goes to the rear brake switch, the rigth handlebar switch and the flasher relay. Unplug those one at a time and see if the light goes out, if it does, you've narrowed your search.

If it doesn't go out with all three of those things unplugged, your short is on the green/white wire. If it does, it's somewhere on the circuit which made the bulb go out when unplugged.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

[R1stu]

[Pete.]

If all else fails jamb a nail in the fuse holder and watch for the smoke
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[R1stu]

[Nobby the Bastard]

Disconnect the battery.

Then check for continuity.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[R1stu]

Ok took a closer look and found it. Turns out that when I put the last engine mounting bracket on, I caught the loom on the right side near the relay plug.

Been bugging me for days lol.
____________________
Carbon closet tart! https://www.bikepics.com/members/r6stuk/02r6/
Stolen bike. 2000 R1: https://www.bikepics.com/members/r6stuk/00r1/
Current bike 1991 Honda ST1100 Pan European, 1986 Honda cb350sg (Finished)

[Nobby the Bastard]

Not really one to say 'I told you so'* but...