Watertight Ignition Starter Key Switch – 3 Positions (Black Plastic, 10A, 3 Terminals + Cap)

This watertight 3-position ignition switch is made from black engineering plastic (nylon), making it extremely lightweight and immune to corrosion. With a 10A rating, it’s designed for smaller engines and electrical systems where the current draw doesn’t exceed that threshold – for example, outboard motors up to about 40 HP, small inboard diesels, personal watercraft, or ATV/UTV vehicles.

Design and durability: Although the housing is plastic, the switch is engineered for the marine environment – the nylon material stands up to UV rays, won’t crack or become brittle in cold temperatures, and won’t corrode from saltwater exposure. This makes it a great choice for open motorboats and jet skis where constant splashing is a factor. Additionally, the switch comes with a rubber cap that snugly covers the key slot. This prevents water from getting inside the mechanism; it’s particularly important on jet skis and RIBs where splashes are frequent. When the cap is closed over the key, the assembly achieves a high waterproof rating (e.g., IP65/IP67), ensuring safety.

Functionality: As a standard 3-position switch, it operates in the familiar way:

• Off (0): all circuits off, engine is stopped, key can be removed.
• On (Ignition): the engine’s ignition system and electrical circuits are powered, ready to start.
• Start: turning to the spring-loaded start position cranks the engine (the spring returns the key to “On” once released).

This is a universal configuration, so the switch can easily replace broken or corroded ignition switches on many models of small boats, ATVs, or even lawn tractors where a waterproof switch is desired.

Installation: The mounting size conforms to standard ignition switch cutouts – about 19 mm (3/4") hole. The plastic nut (or sometimes a metal nut included) secures the switch firmly to the panel. Thanks to its light body, the stress on the dashboard is minimal. The 3 terminals at the back are labeled (B, I, S) similarly to the brass models, making the wiring familiar and easy. It’s recommended to use appropriately sized crimp terminals for a secure connection.

Where to use it:

• In motorboats and small vessels where 10A capacity is sufficient and the light weight and corrosion resistance of plastic are valued. For example, inflatable RIBs with a small console, mini bass boats or skiffs with tiller outboards that have been converted to remote ignition, or small runabouts.
• In jetskis (personal watercraft) – although many PWC have specialized key systems with lanyards or electronic fobs, some universal or older models can use a switch like this. In any case, the waterproof nature makes it suitable for wet environments.
• In off-road vehicles (ATVs/UTVs) that often ford water and mud – this switch can serve as the main ignition switch, providing a more water-resistant alternative to the factory ignition.
• In yachts and sailboats – for auxiliary equipment, generators, or outboard motors on tenders, where a keyed ignition is needed and space or exposure is a concern.

Advantages:

• Lightweight and rust-proof: The plastic housing means no risk of rust, and the weight is negligible – good for small craft where every gram and material durability counts.
• Cost-effective and easy to replace: Nylon switches are generally more economical, without compromising basic function. Replacing a metal switch with this one can be a budget-friendly solution if you don’t require higher amperage handling.
• Safety in wet conditions: The rubber cap plus robust sealing mean you can take waves over the bow or leave the boat in the rain without worrying that the ignition will fail due to moisture ingress.
• Compatibility: The universal design fits many makes and models – from Mercury and Yamaha small engine ignitions to generic control panels for DIY installations.

In summary, the watertight black plastic ignition switch offers the needed level of protection combined with practicality and lightness. It’s an excellent choice for situations where a brass switch might be “overkill” (in capacity or cost) and a standard automotive switch wouldn’t survive. With this switch, your boating (or off-roading) experience will be backed by dependable engine starts, no matter the conditions.