Understanding Relays

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CONTINUITY CHECK FOR PIN ID
If the relay is not labeled, use an ohmmeter and check to see which pins are connected to each other. You should typically find an ohm value of approximately 50 to 120 ohms between two of the pins. This is the control circuit. If the coil is less that 50 ohms it could be suspect. Refer to manual to verify reading. The remaining two pins should read OL (infinite) if it's a normally open relay, or 0 ohms (continuity) if it's a normally closed relay. If the readings are correct, proceed to the next test. Note: If none of the relay pins showed a coil value and all pins show OL or 0 ohms, the control coil is damaged and should be replaced.