Title: Three-Way Switch (Electrical Systems) - Troubleshooting
Course: Troubleshooting Labs > Section: Sample Troubleshooting Component Pages

Troubleshoot a 3-way switch with the continuity setting (Greenlee)

Troubleshoot a 3-way switch with the continuity setting (Klein)

Common Problems

- Failed state 1
  - Check continuity - has continuity from the black screw to the state 1 brass screw regardless of switch position
- Failed state 2
  - Check continuity - has continuity from the black screw to the state 2 brass screw regardless of switch position
- Failed neither
  - Check continuity - no continuity from the black screw to either brass screw regardless of switch position
- Incorrect wiring
  - LTV (Lockout, Tagout, Verify)
  - Verify wires have been stripped and attached properly (observation or continuity)
  - Check incoming and outgoing wires are correct (observation or continuity)
    - Single 3-way - Power in should always go to the black screw and power out should go out of the brass screws
    - Two 3-ways - Power in should go to the black screw and power to the second 3-way should be between the brass screws of both 3-ways.  Power out of the second 3-way should go out of the black screw

Troubleshooting Instrumentation/Tools

- Multimeter (continuity setting)

Troubleshooting Step-by-Step Example

Additional Troubleshooting Information

Related Parts:

2-Way Switch
3-Way Switch
4-Way Switch

Schematic for a two-way (single-pole single-throw) switch:

Where to Purchase:

Lowe's

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