Sierra MP41040 Marine Ignition Starter Switch – 4-Position, Conventional, 12V/15A, with Boot
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Sierra MP41040 Marine Ignition Starter Switch – 4-Position Conventional, 12V/15A, with Boot
The Sierra MP41040 is a heavy-duty marine ignition starter switch built for conventional ignition systems that require an Accessory position. The 4-position action — Accessory, Off, Ignition, and Start — lets you power onboard electronics independently before engaging the ignition, making it well-suited for helm setups with chartplotters, VHF radios, or stereo systems. A corrosion-resistant polyester housing with an inner cylinder seal keeps moisture out and prevents shorts in demanding saltwater and high-humidity marine environments.
A boot is included, providing a finished, weather-resistant seal at the helm panel right out of the box. The 1-1/8" cylinder diameter and 7/8" mounting hole fit a wide range of marine dash panels. The 4-screw terminal layout accommodates conventional ignition wiring with an accessory circuit. Note: no push-to-choke function is included.
Key Specifications
- Part Number: 11-MP41040
- Switch Type: 4-Position (Accessory – Off – Ignition – Start)
- Ignition Type: Conventional
- Voltage: 12V DC
- Current Rating: 15A
- Solenoid: 30A
- Cylinder Diameter: 1-1/8"
- Mounting Hole: 7/8"
- Terminals: 4 Screw
- Housing Material: Polyester (corrosion-resistant)
- Includes: Boot
- Push-to-Choke: Not included
Compatible Applications
- Outboard and inboard engines with conventional ignition systems requiring an Accessory position
- Helm setups with chartplotters, VHF radios, or stereo systems needing independent accessory power before engine start
- Marine dash panels with a 7/8" mounting hole accepting a 1-1/8" cylinder switch
- 12V DC circuits with loads up to 15A
- Direct replacement for worn or damaged OEM 4-position conventional ignition switches
Parts Desk Insights
The MP41040 is the right choice when you need a 4-position conventional ignition switch with a boot included and prefer a modern polyester housing over brass. The boot and polyester construction make it a practical, corrosion-resistant solution for most marine helm environments. If you prefer brass construction for a classic or premium helm aesthetic, the Sierra MP39070 4-Position Conventional Brass Switch is the premium alternative. If you only need a 3-position switch without an Accessory position, the Sierra MP39770 3-Position Conventional Switch (boot included) or the Sierra MP41030 Compact 3-Position Switch (boot included, 5/8" cylinder) are the simpler alternatives. For a 4-position conventional switch without a boot in the same 1-1/8" format, the Sierra MP39800 4-Position Conventional Switch is the no-boot option.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.