The real condenser (condenser same thing as capacitor) testers used a high voltage source but also produced a lot more current than an analog volt-ohmmeter for measurement. Digital volt-ohmmeters have way too much input impedance (practically no measuring current). For a quick test, it's best to use the analog meter and switch to the low ohms range. Make sure the meter has a good battery. The reversing polarity ohm check across the condenser is a quick and dirty check for open (infinity reading) and shorted (zero ohms) conditions. The instantaneous deflection of the meter needle is the capacitor charging or discharging. To properly test the condenser, you need a meter build to test a capacitor/condenser. Today's digital meters, that also measure capacitance, will give a capacitance reading (microfarad etc.) but I doubt the meter is capable of generating a voltage high enough to determine leakage. I suppose a test circuit could be fabricated with a load, a source and ammeter but that's way too much work. It's much easier to round can the old condenser and buy a new one. From what little I have read, automotive condensers are typically between 0.25 and 0.29 microfarads (regardless of 6V or 12V battery) and no less that 600 volts DC (2X the operating voltage of 300 volts DC). The thing about the automotive condenser is that it's usually inside a protective metal can and it's made to withstand heat where the same value capacitor used elsewhere may not. The Mallory company is a name I think of (I'm old-school) when it comes to an American manufacturer. Maybe Bosch (German) is next. Anything coming out of China or Taiwan is an unknown.
