Home › Forum › Ask A Member › Why is it so hard to test a Condenser? (Was: Condensers for Johnson / OMC) › Re: Why is it so hard to test a Condenser? (Was: Condensers for Johnson / OMC)
Since we’re talking condensers, why is it so dang difficult to test them – and what is actually required to spot a bad or failing part?
I have at my disposal several different test instruments. Among them, is a Heathkit IT-28, a "Capacitor Wizard", a generic general-purpose microcontroller-based component tester (which measures value, ESR and Q) and a couple of basic DVMs with capacitor functions.
While any of these instruments can detect an open, shorted or leaky condenser, I’ve yet to find any instrument that can positively identify +all+ or even +most+ flaky parts.
Too many times, all instruments have ‘passed’ parts that turn out to be faulty in actual service.. so now why would that be? You might say it’s a lack of actual operating voltages, but the IT-28 will test caps for leakage up to 600V – plenty high enough for a magneto-ignition condenser. All are capable of reading value and short / open conditions, but again, this just isn’t enough.
So why is that? And ultimately, how would one engineer a test that can reliably detect faulty ignition condensers? Does it require a full HV circuit test – where the condenser is used in a mock-up ignition circuit, and the spark voltage / current / quality is quantified based on maximum gap, etc?
In all my years, I’ve never come across an adequate answer to this.. so why not try asking again.