Dead 1200 sport.

Having completed a trouble free 700 mile trip last weekend, i was a bit miffed to find my bike was completely dead this morning. Nothing. Zilch. Turn key and … nowt! Turns out battery was completely flat, no indication of a problem last week to flat. Less than 2 years old. Very odd. However, also found that one of the 30 amp main fuses was blown,so my question is this. Could that blown fuse stop the battery recharging when the bike was running? And i’ve simply been lucky that there was sufficient charge in battery to get me home last weekend without noticing an issue?

The 30A fuse is the main ignition fuse. So your train of thought could be right. I don’t know if it would stop the charging system.

There are two 30 amp fuses, both described as ‘main’ fuses. I’m just not sure that the flat battery and the blown fuse are linked? I would have expected the battery warning light to have come on if it wasn’t charging. I don’t know. It’s on charge tonight, i’ll see what tomorrow brings!

Ok. Put in charged battery, started no bother, toggled the menu until showing battery volts @ 13.8 all good, yes?
Removed the 30a fuse i had replaced and voltage started dropping straight away, no warning on dash to indicate a problem! Replaced fuse and voltage increased again. So i’m going to say fuse was the problem. I’m going to leave bike overnight now and hopefully the battery won’t have discharged and it’ll start ok tomorrow.
Fingers crossed !

Now the hard bit . Finding what caused the fuse to blow,

That’s not good!!!

Ok , left bike 2 days, started no bother today , done 90 odd miles , wee day trip to Thistle rally, had the dash set to show battery voltage, showing 13.9 /14 all day so hopefully this issue is resolved. If only i knew why the fuse blew??

Could be an age thing, where the fuse is fatigued from being heated up and colled a lot of time and failed?

Bugger! done it again, bike been unused 5 days , went out, nothing. completely flat battery again! 30a fuses all ok this time, so, something is intermittently draining the battery…I hate crap like this.

Sounds like it’s swap relays round time or change all the relays go to a motor factors with one of your relays you will save a lot of money and grief from past experience guzzi relays ain’t to good hope it works all the best Derek.

Please be aware that the injection relay has a diode in it as it goes to the ECU, it is possible to swap most of them around.

I did find that water can get into the injection relay.

Ok. Turns out there is nothing wrong with bike (touch wood) . I have (had) a small solar charger on garage roof, these are designed not to charge a flat battery but to feed a very small charge to keep a battery topped up. Flat battery scenario only happened in my garage when charger was connected. Seems like it was draining instead of charging. Bike has done over a 1000 miles since last problem which was the last time charger was connected !