electraphobia

[RealityRSV]

the amount of times i've struggled to fix probably basic faults with bike electrics... doesn't even help me much looking in my haynes manuals as it kinda assumes you know a bit about what your doing, and clearly, i dont. i know how to check and change fuses and bulbs, how to wiggle cables for loose connections, how to charge a battery just to give you an idea of my current competance. so if you have any general tips tricks or essential info on how to tackle the most common jobs on a bike then i'm asking for your help... starting with understanding watts, amps etc. anybody?

[Strappy]

Me too. I bought a multimeter years ago at a BMF show, still haven't worked out how to use the fucker. Although it did help me check a connection on my old car on the basis that "these connections have a number, these ones don't".

I swear I'd have better results from licking my fingers and sticking them on the mains.

[gregtrx]

I found this on google, maybe worth a look for the very basics. In terms of bikes, things aren't too bad. Most of your problems, if your aprillia is anything like my old one, will be in basic things like connections not being made and melted insulation in the loom after the bleeding thing chafes on the subframe (that wasn't design just poor routing by someone).

Checking things like the windings on coils to see if they have the correct resistance against the owners manual and whether your battery is charging properly by looking at the volts when the engine is running is about as hard as it'll get I think. The biggest ballache is accesability to find the problem, especially if it's something like a damaged wire as the loom goes past the headstock causing problems. Cleanliness of connections is an issue too, the connectors in the blocks can oxidise over time and then make a poor connection, which will either stop something working or create a high current draw which will melt the block if you're unlucky. Contact cleaner and dielectric grease are your friends.

As for multimeters, you'll want to be using the resistance setting for checking continuity from one point to another (or it may have a beep setting which is useful for tracing wires), the voltage setting for looking at battery/charging issues and that's about it. Be careful not to try and read battery current unless you're sure the meter is rated for the amps you can get out of the battery, which is quite high. The ideal voltmeter (when in that mode) has infinite resistance, so it's not a problem looking at volts.

[Number 6]

Building up the Katana over the last year and a half has thrown up a few electrical problems and I have found one of the most useful bits of kit to be a test light which I made up myself.

[RealityRSV]

cheers for the link above, thats a good start. the problem i'm trying to work out at the moment is actually on my nc30, which i crashed a few weeks ago breaking one of the indicators. i've just received some replacement indicators and tried fitting one, but none of them are working. when i turn the switch on in either direction i can hear the relay clicking intermitantly and randomly but no lights are illuminating.

how do i check the following:

can i assume power is reaching the relay fine or do i need to check enough power is reaching the relay to make it function properly?

how do i use a multimeter to check the output at the relay (do i use one of the probes at the output wire and the other to earth?)

can i do a simple check of the indicator unit by offering up the wires to a 12v battery or will the voltage be too much for it?

on a simple bulb circuit does it matter which way round the wires are connected? (i seem to remember it doesn't for a normal bulb, but things like l.e.d's will only work one way)

[gregtrx]

can i assume power is reaching the relay fine or do i need to check enough power is reaching the relay to make it function properly?

how do i use a multimeter to check the output at the relay (do i use one of the probes at the output wire and the other to earth?)

can i do a simple check of the indicator unit by offering up the wires to a 12v battery or will the voltage be too much for it?

on a simple bulb circuit does it matter which way round the wires are connected? (i seem to remember it doesn't for a normal bulb, but things like l.e.d's will only work one way)

It's odd that none of them work, I wonder if you have a short anywhere on the indicator circuit. To check the relay put the black probe on ground (some bare metal somewhere, engine bolt maybe or wherever is convienient) and the red one on the output, should cycle between 12 V and 0 V as the flasher unit kicks in. You can test the bulb on a battery, if there are no problems with the connections it shouldn't blow, but you could always make up a test lead with an inline fuse (fuse and holder from halfords or a motor factors). probably something like a 5A or 7.5 A on the lighting circuit, check the fusebox.

With an incandescent bulb (with a fillament) it's current through the fillament that makes the light, and it doesn't matter which way it goes.

It might be worth seeing if one of your +ve feeds for the indicators shows continuity to ground, maybe a wire got trapped somewhere in the drop?

I'm not great with electrics myself, but if you approach it calmly and think about things before you jump in it's a lot easier (brews help too, as does a nights sleep if you're chasing your tail trying to sort a problem).