This is a 12V, 100A normally-open heavy-duty starter/battery relay. In simple terms:

• Voltage: 12V DC

• Current rating: 100A

• Type: Normally Open (NO)

• Pins/terminals: 2

• Small terminals/pins: Control voltage

• Large terminals: Battery/load connection

• Typical uses: Car battery ON/OFF control, starter circuits, preheat systems, agricultural machinery, and small cranes

• Package: 1 × relay

• Size: 4.3 × 4.5 × 8 cm

How it works

When the relay receives the required 12V control voltage, it closes the high-current circuit between the large terminals, allowing current to flow to the connected load. When the control voltage is removed, it opens the circuit.

Important: The description says “2-pin relay,” but the wiring description mentions small control pins and large load terminals, which may indicate multiple physical terminals depending on the exact WM686 version. Verify the terminal layout on the actual relay before connecting it.