gt380 15A main fuse blowing

Ramjam · Post by **Ramjam** » Fri Mar 21, 2014 8:56 am

Hi all
I just did a major rebuild and today went for a long spin on the bike, with everything working very well, including all electrical parts.
But when i restarted the bike a second time when it was cold, it ran for about 10 seconds and then died suddenly and i noticed that the fuse was blown. I replaced the fuse a second time and it blew. then a third time and it was ok for about 3 mins before blowing.

where is the most obvious place that red power cable could be earthing? under the tank? in the headlight bowel?

Could i disconnect that red wire and run a new one directly to the bowel of the headlamp to narrow it down? where would the panel 'stick' the new red wire?

please help all you can. many thanks

jabcb · Post by **jabcb** » Fri Mar 21, 2014 9:49 am

Does the fuse blow when you have the lights switched off & the engine kill switch set to off?

Ramjam · Post by **Ramjam** » Fri Mar 21, 2014 10:49 am

jabcb · Post by **jabcb** » Fri Mar 21, 2014 2:30 pm

That makes it easier to find because it eliminates a lot of the wiring.

With the battery removed, key in on position, lights switches off & kill switched set to off,
use your multimeter to check resistance at between the two wiring harness battery connections.

With the multimeter lead in one direction you should get really high readings & with the meter leads flipped you should get low readings. That's because the multimeter battery power passes throughout the rectifier in one direction & not the other.
What are the readings?

Now disconnect the voltage regulator & repeat.
What are the readings?

Now disconnect the rectifier & repeat.
What is the reading? (you only need to check 1 direction)
At this point you should get an open circuit reading. (What the multimeter display says depends on the meter.)

If you don't have an open circuit reading, remove the headlight.
What is the reading?

Ramjam · Post by **Ramjam** » Sat Mar 22, 2014 1:09 am

thanks so much for your help. I actually identified the red power lead from the battery pinching against the battery casing causing the short so i didnt need to go through the step-by-step guide which you kindly wrote.
and thanks so much for your sharp observation with the photo. You've got good eyes to spot that indeed the middle cap was indeed non NGK and non resistor. I just took it off and saw that for myself after your comment

cheers

mj

gt380 15A main fuse blowing

gt380 15A main fuse blowing

Re: gt380 15A main fuse blowing

Re: gt380 15A main fuse blowing

Re: gt380 15A main fuse blowing

Re: gt380 15A main fuse blowing