With the price of electronic goods from the far east at an all time low now is the time to buy yourself a digital multi-meter. No need to buy especially designed for car maintenance as general purpose ones are much cheaper.
Ideally for car work look for one that has the following features:
- DC Voltage scales of 0-2 volts and 0-20 volts DC.
- AC voltage scale of 0-20 volts (although a 0-200 volts will do).
- Resistance scales of 0-200 Ohms and other ranges up to 0-2M Ohms.
- A continuity tester with buzzer.
- DC Current Measurement up to 10 Amperes.
- An input impedance of greater than 1 M Ohm.
Prices for basic units start at about £7.00 to well over a £1000.00 but I use and recommend an Academy PG10B, available from Maplin part number GW18U price £24.99 including VAT.which lacks a 0-20 Volts AC scale but is still fine for checking cranking voltage output of the Crankshaft Angle Sensor (CAS) on Lucas and MEMS systems. I have been using and abusing mine for 2 years without any problems. If buying another make of unit examine the quality of the test probes very carefully as poorly made ones will give a lot of trouble.