K5 SVS Electrical Weirdness

[fizzwheel]

Righto.. Liz's bike is playing up again...

It blew its main fuse a while back and we never got to the bottom of it, but once the fuse was replaced it hasnt blown again, but now someting else is going on.

the bike will start and run all the electrics work, but quite frequently now the whole bike will die, all the electrics go, and everything including the engine cuts out, she also says that before it does this sometimes the speedo goes nuts and starts showing stupid speeds such as 186mph.

We've found if we take the seat off, and wiggle the fuse holder about then that sometimes fixes the bike and it comes back to life, but when you bolt the seat back on the the electrics go again, i.e. nothing works, no dash lights, no headlights, no fuel rail prime, nothing.

I'd like to get this fixed without taking it somewhere, as we are both a bit skint.

We havent done anything to the bike for ages. The last thing I did was fit a new rear indicator as the previous one packed up due to water ingress rusted the bulb holder up so much I coudlnt take the bulb out of it.

Liz has a harness for a set of Oxford Hot Grips and her Gerbing heated jacket on the bike as well. But these have been on there for ages with no problems.

So I'm thinking

Chaffing wires somewhere, possible seat bolts ?
Take off the hotgrips and the Gerbing harness' and see how the bike runs like that.
Failing that pull the rear plastics off and have a good poke around the rear subfarme, also get the tank up and have good look round the airbox, headstock for chaffed wires.

I think its something going on related to the seat bolts as thats when it seems to stop working.

Bit stuck with this so could use some help

Ta

[yorkie_chris]

Speedo wierdness and such is strange, indicates to me that it's losing power somewhere.

Check for chaffed wires and especially loose contacts, if the main fuse is loose in its holder this could give such problems. If that doesn't cure it then try run another cable from battery -ve to the frame

[SoulKiss]

Nothing much to add, except to ask that when it goes "funny" does the clock reset the time.

If it does then that indicates total isolation of the battery at some point.

Might help with the diags

[fizzwheel]

Originally Posted by SoulKiss

Nothing much to add, except to ask that when it goes "funny" does the clock reset the time.

If it does then that indicates total isolation of the battery at some point.

Might help with the diags

I'm not sure I didnt ask Liz about that, I'll have a look when I get home.

Thanks for the responses so far.

Kick it...


... or hit it with a hammer.





I'm not helping am I.

[jambo]

I'd say loose connection / chaffed wire, or a dodgy main relay. Take each connection out, clean it up with a wire brush, use a little grease and tighten it back up properly. Check the wires in the area for the insulation having rubbed through.

Jambo

The speedo going haywire is generally an indication that the alternator is shot. I've had it on both cars & bikes in the past. You'll probably notice that the rev counter goes haywire too. For example, you show you're doing 186mph (limit on the ECU for the display just FYI) but you're doing 500rpm, when the engine clearly sounds like a steady 6k rpm.

As the alternators are on their way out, they start putting out too much voltage, which explains why the instuments go haywire. They also put out too much current, which explains the blown fuses.

Cost me an arm and 3 legs when it happened in the car - £360 for the parts alone!

Check the charging circuit (from the alternator, through the reg/rec to the battery). That should put you on the right tracks.

Note: Get this checked quickly, a duff alternator is bad enough, but when it goes, it'll probably take out the reg/rec if it hasn't already.

[fizzwheel]

Could also be that the Positive terminal on the battery was loose.... having had a fiddle with the bike today thats what I think the problem was...

Might be wrong, need to try the bike again before we go down the bust alternator more complicated route first, but thanks for the suggestion Baph much appreciated.

[Viney]

If the fuse has popped, then it could be the loom rubbing on the subframe.

How many miles has it got on it now?

[fizzwheel]

Originally Posted by Viney

If the fuse has popped, then it could be the loom rubbing on the subframe.

How many miles has it got on it now?

I was thinking that but I had a good poke around it yesterday and I cant see anywhere, I guess to be sure we'll have to take the rear plastics off.

I think its somewhere in the region of 35K ish...