T500L blowing fuses

[malky]

Hi guys my T500L has suddenly started blowing fuses - it will go for months with no problem and then suddenly blow a couple one after the other - it only seems to happen when both brakes are used heavily - i've put new brake light switches on both front and back and checked all the wiring but cant see anything obvious - the only thing that i have noticed is that with a fully charged battery and with the engine off i'm only getting 10 volts at the connector block at the rear light so I'm missing 2 volts somewhere

[Madbuffalo]

Yes it seems likely you've got a wire grounding out somewhere and that can be hard to pinpoint unfortunately as you're finding. You could check resistance from the battery positive to the frame - that should be infinite while the bike's off. If it's not you could isolate sections of wiring and check resistance to ground to narrow down the location and the brake system could be a good place to start since you're finding a voltage drop there. Hope you get it figured out.

[jabcb]

Check the wires around the battery box. By chance on a 75 T500, I noticed a wire with the insulation nearly worn completely thru.

[malky]

thanks guys,
have fitted a resettable trip fuse in the circuit now along with new brake light switches and ignition switch and cleaned every connection that I can see and so far so good - still only getting 10v at the rear light though but another T500 that I have is the same in that respect