Troublesome Yamaha sr125 help!

[ben10cunningham]

I have a yamaha sr 125 2002 model, it was running just before christmas except after about 5 minutes would cut and run unhealthily, i diagnosed this as a faulty ignition coil and bought a new one and replaced.

By the time i had done this my battery had died so i charged it back up to find it was continuously blowing the main 20A fuse beside the battery. Without the key even being in nevermind on. (I had tried to jumpstart off of a car in the meantime when battery had died).

The fuse blows after about 10 seconds but before this happens the left indicator is stuck on constant beam. I have tried unpluging to find the fault to no avail.

Have i fried the computer? Any ideas or troubleshooting/diagnostics i could do? Any help appreciated as it has sat around all winter and i am itching to get it going again.

[Tango]

Never try to jump start a bike from a running car, there's too many amps available and can cook things in the bike electrics.......

I'd unplug the Regulator/Rectifier and try another fuse.....just in case it's the Reg/Rec that's cooked.....

[ben10cunningham]

Ive tried unpluging everything one by one and it does the same and thats before i even put they key in.

[megawatt]

Is the engine trying to turn over? Sounds like problem with starter solenoid.

[Tango]

Ive tried unpluging everything one by one and it does the same and thats before i even put they key in.

 

Sounds like some wiring shorting to the frame or engine......Unfortunately, if it is that, it'll take some finding......

[ben10cunningham]

Is the engine trying to turn over? Sounds like problem with starter solenoid.

 

Nothing is happening. When the key is out and off the left indicator is on solid as soon as i put a new fuse in. Then fuse blows after couple of seconds.

[Grumpy Old Git]

Ive tried unpluging everything one by one and it does the same and thats before i even put they key in.

 

Sounds like some wiring shorting to the frame or engine......Unfortunately, if it is that, it'll take some finding......

 

Easiest ( ) way to find the problem is to disconnect all connectors in the main loom and re-connect one at a time until the fault re-appears, then 'chase' down that 'branch' to find the issue. No quick (or even easy as you may have to remove the tank to get to the main connectors).

[JRH]

Is the engine trying to turn over? Sounds like problem with starter solenoid.

 

Nothing is happening. When the key is out and off the left indicator is on solid as soon as i put a new fuse in. Then fuse blows after couple of seconds.

 

Have you disconnected the rectifier?

As the fuse is NOT blowing imeadiatley it is not a direct short to the frame. You have a very low resistance fault which will not be easy to find. However looking on the net I can only find wiring diagrams for 97 and 99 models so hoping there are no main changes the fuse only feeds 2 places. The main switch and the rectifier.

So disconnect the red wire from the output of the fuse. And try. It should be ok.

So disconnect the red wire from the main switch and the rectifier / regulator.

Then refit the fuse and try again. Hopefully the fuse will not blow.

If it does blow the problem is somewhere in the red cable between the main switch and the rectifier. So visually check this part of the wiring loom.

If it is ok then remove the fuse and reconnect the main switch and try again. Hopefully this will be ok. If so the problem is most likely the rectifier as I think Tango suggested.

You could then connect the rectifier and if the fuse blows then that is the culprit.

I think the indicator is a separate issue.