How To Test A Capacitor
This short video shows How To Test A Capacitor. Capacitors for air compressors can be tricky due to the nature in size and the different ratings. We give a brief explanation here. If in doubt, then always check your manual or call the manufacturer for information.
How to Test a Capacitor
1. Disconnect capacitor from motor and discharge with insulated screwdriver across terminals.
2. Set your ohmmeter to highest scale; connect one lead to each terminal on the capacitor.
3. If needle drops to zero and stays at zero, capacitor is probably shorted.
4. If needle remains at a high value, capacitor is probably open.
5. If needle drops to zero and slowly rises, capacitor is probably good. You may also troubleshoot capacitors by means of a simple "Capacitor Tester" which generates an audible sound for testing.
Note: Master Tool Repair claims no responsibility for injury, dismemberment or accidental death. This document is for information purposes only and all testing performed using this material is at the discretion of the individual performing this test.
Recent Posts
-
Air Compressor Pumps 101: Understanding the Heart of Your Machine
If you rely on compressed air for your workshop, automotive garage, or industrial facility, you know …Jul 1, 2026 -
Common Mistakes to Avoid When Repairing Your Air Compressor
Fixing your own air compressor is an excellent way to save money, minimize project downtime, and ext …Jun 25, 2026 -
Ditch the Rust! Manual vs. Automatic Air Compressor Drain Valves
Every time you run your air compressor, physics works against your machine. As air compresses, it he …Jun 18, 2026