19-07-2022, 11:55 AM
Hi JonE
For the full story on condensers, read my article on the DA7C website. However, to summarise, early type condensers made with paper tend to fail short circuit especially under voltage stress. If really bad you will see a finite resistance with a modern digital ohmmeter, once you have waited for the reading to settle. Probes either way round, doesn't matter. Any that don't show essentially infinite resistance can be chucked. Any that pass MIGHT be OK
Modern condensers made with plastic suffer from high series resistance due to poor manufacturing technique. This sometimes shows up only when hot. No easy way to test other than by substitution in a working engine. An ignition setup with a condenser failed in this way can be brought back to life by bridging a good condenser in parallel.
For the full story on condensers, read my article on the DA7C website. However, to summarise, early type condensers made with paper tend to fail short circuit especially under voltage stress. If really bad you will see a finite resistance with a modern digital ohmmeter, once you have waited for the reading to settle. Probes either way round, doesn't matter. Any that don't show essentially infinite resistance can be chucked. Any that pass MIGHT be OK
Modern condensers made with plastic suffer from high series resistance due to poor manufacturing technique. This sometimes shows up only when hot. No easy way to test other than by substitution in a working engine. An ignition setup with a condenser failed in this way can be brought back to life by bridging a good condenser in parallel.