Some Electrical Tips

[Kiwi_Roy]

I have messed electrics over the past 50, some of what I learned stuck.

Since buying my V11 Sport last year I have been exposed to a whole range of gremlins.

 

Short Circuits

If you have a short circuit on the bike and can't locate it before the fuse blows, remove the fuse

and substitute a high Wattage lamp (solder a couple of wires to an old headlamp works great).

The lamp will pass enough current to power the circuit, (even the headlight will light up dimly) but

as soon as you get a short it will glow at full brightness. This lets you wiggle all the wires around

looking for when it opens/shorts.

Tape over any exposed live contacts on the lamp, you don't want a short.

Caution, unplug the ECU before doing this with F1/F2.

And I don't mean ride the bike like that

 

Intermittent Open Circuit

Here's a trick electricians use.

If you have a point X you suspect is loosing power take a spare relay, wire it's coil in series with the normally open contact

then connect it to point X and negative (chassis)

Energize the coil by shorting the contacts for a second. (You can get fancy and add a push button)

As long as your point X has power the relay will stay energized but if it looses power for even a split second the relay will

open and stay open.

Of course if you turn the key off the relay will drop out.

You can add a light across the coil or to a normally closed contact. it doesn't really matter just as long as you know if it's

energized or not.

I knocked mine up using one of the old Siemens relays, pushbutton and an LED. I have the relay under the seat and just connect

to wherever I need to test. The light and pushbutton just hang out the front of seat where I can see them.

 

Relay Testing

The best spot to test a suspect relay is R1 spot, there both contacts are used and some fairly heavy currents flow, The R2 spot is

good if you suspect the relay is dropping out, you will soon notice if it opens there as the tacho will drop to zero.

Warning - don't do your testing at night, loss of lighting is not good!

 

Measure current without an ammeter.

All you need is a digital multimeter with a mV scale.

Take a short length of wire sized for the current you need to measure and look up the volt drop tables (most assume there and back

so you have to thing double)

Figure out how much length you need for a 1 or 10 mV drop at 1 amp

Bare the wire at two points that far apart and connect the meter there.

Although copper wire is not the best metal to use as a shunt, it works reasonably well, is cheap, well insulated and can safely take an

overload of 100% or more for a short time. The meter connection is not made at the end to avoid stray voltages made by contact resistance

A word of warning - The small meter leads are live so don't let them make contact with exposed metal. A couple of meter jacks works well.

Troubleshooting Tips.pdf