Watertight 4-Position Ignition Starter Key Switch (Brass, 15A, 4 Terminals + Cap)

This 4-position watertight ignition starter key switch is built to meet the demands of the marine environment, where reliability and water protection are paramount. The brass body ensures durability and corrosion resistance – even with daily use and exposure to saltwater, the switch maintains its functionality.

The 4 positions of the key switch provide flexibility in managing your boat’s electrical systems:

• Off – all engine and accessory circuits are off; the key can be removed in this position.
• Accessory (ACC) – powers auxiliary equipment (e.g. radio, navigation instruments) without turning on the engine’s ignition.
• Ignition On (ON) – powers the engine’s ignition/engine electronics (fuel pump, ignition coil, dashboard gauges), putting the system in ready-to-start mode.
• Start – a spring-loaded momentary position that engages the starter motor; releasing the key returns it automatically to the “ON” position.

Thanks to the extra ACC position, this switch is ideal for boats outfitted with electronics you want to use without running the engine – for example, a stereo or GPS while at anchor. Additionally, the fourth position can be utilized for activating glow plugs on a diesel engine (in certain wiring setups) before cranking, making this switch suitable for a variety of engine types.

Watertight design and construction: The switch comes with an attached rubber cap that snugly covers the key slot when the key is inserted. This keeps out rain, sea spray, and moisture from the lock mechanism. The backside of the switch (where the terminals are) is fitted with a gasket and rubber O-rings to further shield the contacts from corrosion. As a result, the entire unit meets marine watertight standards (IP67 or equivalent), which means it’s safe for installation on exposed dashboards, RIB console panels, or a flybridge helm.

Electrical characteristics: The brass contacts provide low resistance and can handle currents up to 15A – ample for the ignition circuit of most inboard and outboard engines, as well as triggering a starter solenoid. The four rear terminals are clearly marked, allowing straightforward wiring of the circuits: Battery feed, Ignition output, Starter output, and Accessory output. The wiring schematic follows the marine industry standard, making integration into your boat’s system hassle-free.

Installation: The threaded mounting stem of the switch is a standard size (typically Ø19 mm or 3/4”), which fits common dash panel holes. A mounting nut and washer are included for securing the switch to the panel. Installation is simple – drill a suitable hole at the desired location, insert the switch from the front, and tighten it from behind with the nut. After connecting your wires to the terminals (using crimped ring or spade connectors is recommended), your new ignition switch is ready to use.

Advantages:

• Reliability: The switch mechanism is rated for many on/off cycles, ensuring a long service life. The brass construction won’t rust, and the connections remain secure even under constant vibration.
• Safety: The watertight design eliminates the risk of short circuits caused by water ingress, protecting your boat’s electrical system. The rubber cap also keeps out debris or dust that could otherwise jam the key slot.
• Versatility: This model can replace or upgrade existing ignition switches on various boat brands. Its universal design and standard key (comes with two matching keys) make it suitable as a replacement or primary ignition for a wide range of marine engines.

With the watertight 4-position brass ignition switch, you get a professional-grade starting solution that withstands harsh conditions. Whether you operate a fishing boat, a speedboat, or a sailing yacht, this switch gives you confidence at every turn of the key – your engine will crank reliably, and your electrical system stays protected.