Is there anyone prepared to teach this North Shore Auckland dumb-bunny how to use a multimeter for simple diagnostic work on the bike?  I'm familiar with Ohm's Law, but have been limited to using the multimeter solely for determining battery voltage.  There must be other worthwhile uses!   If there are other dumb-bunnies with similar needs perhaps group tuition could be an option?  Practical hands-on tuition would be appreciated. 

Rip into any autoelectrical workshop or electrical retailer close by. I'm sure there will be someone who'll show you how to use a multimeter.A multimeter just combines the functions of an ammeter, a voltmeter and an ohmeter (possibly some additional functions too). An ammeter measures current, a voltmeter measures the potential difference (voltage) between two points, and an ohmeter measures resistance.Think about the changes you would have to make to a practical circuit in order to include the ammeter. To start with, you need to break the circuit so that an ammeter can be connected in series. All the current flowing in the circuit must pass through the ammeter. Meters are not supposed to alter the behaviour of the circuit, or at least not significantly, and it follows that an ammeter must have a very low resistance.With voltmeters however, you do not need to break the circuit. The voltmeter is connected in parallel between the two points where the measurement is to be made. Since the voltmeter provides a parallel pathway, it should take as little current as possible. In other words, a voltmeter should have a very high resistance.Which measurement are you thinking might be the more useful? In my experience, voltage measurements are used much more often than current measurements.The processing of electronic signals is usually thought of in voltage terms. It is an added advantage that a voltage measurement is easier to make. The orginal circuit does not need to be changed. Often, the meter probes are connected simply by touching them to the points of interest.An ohmmeter does not function with a circuit connected to a power supply. If you want to measure the resistance of a particular component, you must take it out of the circuit altogether and test it separately. Ohmmeters work by passing a small current through the component and measuring the voltage produced. If you try this with the component connected into a circuit with a power supply, hopefully the fuse installed in the multimeter will do its job.Have funGarry