St1300A2 - Serious Earth Leakage

My 2002 Pan faltered and then shut down one day, three weeks ago.
I have not been able to start it since then because as soon as I switch on the ignition the battery voltage plummets and continues to fall away.
The fuel pump is heard to run and everything else clicks in. Every thing seems normal when I switch on the ignition and turn the engine over except the rapid loss of voltage and the engine does not start.
A volt meter connected across the battery terminals confirms that there is a serious earth somewhere and as yet I can't find it.
I have pulled all the fuses and the relays, under the lift handle on the left side, one at a time but when the ignition is switched on the voltage steadily falls away without interruption!

Any suggestions as to how to go about finding the earthing source would be much appreciated.

Regards,
rossjeal in the UK

Don't overlook the dying battery potential.

Have you tested and confirmed that the battery is ok? A healthy battery losing voltage that fast due to a short circuit would be creating a lot of smoke from something,

Charge the battery and then load test it. I bet it fails.

How would you propose to 'load test' it exactly and what would constitute failure?

1. Take it out, charge it then take it to an auto shop or battery shop and get it load tested.

or

2. Leave it in, charge it. Turn on lights for one minute without engine running. Turn off the lights and take a voltage reading, should be 12.7 volts, if less your battery is already suspect. Keep the voltmeter leads between the terminals and attempt to start the bike. If the reading is less than 9.5 volts while trying to start, your battery is bad and needs to be replaced.

+1 on the battery as the culprit. You may have a dud there.

Keeping the voltmeter leads on the terminals would be the way to go.

rossjeal said:

How would you propose to 'load test' it exactly and what would constitute failure?

Click to expand...

Auto shops have a gadget with large resistors inside and a voltmeter attached to the leads. They connect it to the battery, and the resistors covert the electricity to heat (this is the 'load' across the battery terminals). The voltmeter shows the voltage under load (the same as measuring the voltage while you are cranking the bike - or car).

The answers above give you the voltage for a good or bad battery, and your headlight is the load here. Certainly a lot faster than pulling the battery and taking it to a shop that might ask for $$$ for the load test (tho most good shops will do this for free - hoping you buy a new battery). Battery shops will almost certainly do it for free.

iNGARS said:

This connector connects all the grouns wires of the bike.

Click to expand...

How would that make the voltage drop? Bad battery is my bet.

The Dan said:

How would that make the voltage drop? Bad battery is my bet.

Click to expand...

you're right.
I had a problem with my google translate
and seems symptoms that had appeared on my bike

Updated on Serious Earth Leakage thread!
The battery may not be the problem after all.
Now, having checked that the fuel pump starts when the ignition is switched on and that the spark plugs are all performing well I'm beginning to suspect a dud fuel injector or two.
The engine failure was almost immediate with briefly erratic firing, then silence. Many attempts to restart it at that time resulted in battery voltage decay!
Now, with full battery voltage the engine turns over normally and if no throttle is applied the engine is heard to fire very weakly. With my finger still on the start button, if the throttle is now opened the firing ceases but the speed of the engine rotation increases. This latter fact suggests to me that fuel is entering some of the cylinders, if not all. The problem might therefore be with dud fuel injectors or individual fuel pump chamber failure but how do I check these theories before engine strip down?
Any proposals would be appreciated.
Ross Jeal
Wales, UK

Your first step is still to verify the battery isn't weak, but it sounds like it has somehow gotten stronger than in the first report, any explanation for that? I'd try to jumpstart it from a non-running car to see if battery strength has anything to do with it.