Non-Guzzi Electrical Problem

On a Japanese bike – who would have thought? A question here for you sparkies if perhaps you could indulge me. Chris – this means you.

My pal has a recently purchased Yamaha XT225 Serow c. 2003 vintage. All pretty much std though it has some bolt on hot grips – these appear to have been hard wired onto the battery, as in they are still live when the ign is off.

We were out tailing all weekend and on Saturday his bike was going just great, all day. Sunday morning at first switch on the electrics all appear to be totally dead. Except the LED for the hot grips will light up when they are switched on (see note above). The bike has no kicker and the starter is also dead of course. But with a hop a skip and a bump the bike fires up OK. But the lights are not working right – no neutral light and the indicators will only glow weakly. Except if he switched the main lights on then everything is working just fine and dandy. Weird.

So every time he shuts it off we’re back to a bump start. We’re gonna pull all of the covers and have a good look over – maybe for a loose battery terminal. Any other pointers from you folks?


Is it possible that the heated grips were left on and they have drained the battery? Was there any problem before your recent trip? Was there any problem before the heated grips were added?
I would suggest giving the battery a good charge and cleaning up all of the battery terminals. I’m not sure why all of the lights work with the headlights on, it sounds counter-intuitive.
It is advisable only to wire such accessories into a circuit that is turned off by the ignition switch to prevent battery drain if they are left on.

Thanks Chris.

This was the first run out for the bike since he got it. The grips were defo not left on, as he nearly did that and we all noticed and they were switched off.
Grips were already added by the PO. Agree entirely on putting in a switched relay – I’ll be doing that when we lift the covers to fix this problem and give the bike a general once over.
And yes – counterintuitive. Sounds like the reverse of a bad earth. Too good an earth … ? Does not compute. Weird.

This suggests an extra alternator winding is switched in for the headlamp, and the low power winding (non headlight) isn’t doing anything. Or could be rectifier. Or bad connection in that general area.


OK thanks. Gives me some pointers. I don’t have the bike to hand for the moment but will report back when I know more. Cheers.

Be interested what you find!

Sounds to me like a dead battery but why is everything coming back to normal when the lights are switched on?
Earthing problems can produce some really weird effects that are totally incomprehensible.
Dodgy corroded connections are more likely than a failed component.
A quick Google search comes up with a wiring diagram
and a forum