In this video Bob shows us how to test for ohms and continuity in a handlebar switch control harness. A multimeter becomes a very important tool when performing repairs or upgrades beyond basic maintenance.
An individual wire, handlebar switch or circuit has to be isolated whenever testing for ohms or continuity. That is the circuit cannot be powered or grounded in any way. It must be complete and uninterrupted on its own.
Testing for continuity or ohms resistance is important when diagnosing a failing circuit such as a bad brake switch or turn signal. It can also be very helpful to double check your work when doing an extensive wiring procedure such as internally wiring handlebars, replacing a main harness, or simply changing signal light housings.
Remember, a wire or circuit can have continuity but if ohms resistance is too high, the function will fail to operate, or not operate correctly. This is very important when testing the stator in your charging system. If resistance is high or elevated, it will explain a weak AC output. If your stator has continuity to ground, it is often an indication that the stator is actually damaged or broken.
The demonstration Bob and Mark give us is only on the Softail right side handlebar switch, but it is a good window on how almost everything functions on a 12 volt system. When an ECM is involved, there may be some low voltage functions but testing these functions, or circuits will be virtually the same.
If an electrical issue arises on your motorcycle, don’t be one of those guys that says “I do all my own work, but I don’t touch anything electrical”! Grab a test light and a multimeter. Play around with them a little bit.
Electrical theory is not something that you will grasp immediately, so start with trying some easy tests. If you approach things safely, there is nothing that should intimidate you.