Operation CHARM: Car repair manuals for everyone.

Repair and Diagnosis: Testing and Inspection

Power Relay Test

Relays - Power Relay Test:




Use this chart to identify the type of relay, then do the test listed for it.

Normally-open type A










Check for continuity between the terminals.
- There should be continuity between the No.1 and No.2 terminals when power and ground are connected to the No.3 and No.4 terminals.
- There should be no continuity between the No.1 and No.2 terminals when power is disconnected.

Normally-open type B










Check for continuity between the terminals.
- There should be continuity between the No.1 and No.3 terminals when power and ground are connected to the No.2 and No.4 terminals.
- There should be no continuity between the No.1 and No.3 terminals when power is disconnected.

Five-terminal type










Check for continuity between the terminals.
- There should be continuity between the No.1 and No.2 terminals when power and ground are connected to the No.3 and No.4 terminals.
- There should be no continuity between the No.1 and No.4 terminals when power is disconnected.