Sierra MP39070 Marine Ignition Starter Switch – 4-Position, Conventional, Brass, 12V/15A
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Sierra MP39070 Marine Ignition Starter Switch – 4-Position Conventional, Brass, 12V/15A
The Sierra MP39070 is a premium brass-bodied 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 modern helm setups with chartplotters, VHF radios, and stereo systems. Solid brass construction delivers time-tested corrosion resistance with a premium look and feel that suits classic, traditional, and high-end marine helm panels.
The 1" cylinder diameter and 7/8" mounting hole fit a wide range of marine dash panels, and the included boot provides a finished, weather-resistant installation. The 4-screw terminal layout accommodates conventional ignition wiring with an accessory circuit. Note: this switch does not include a push-to-choke function.
Key Specifications
- Part Number: 11-MP39070
- Switch Type: 4-Position (Accessory – Off – Ignition – Start)
- Ignition Type: Conventional
- Voltage: 12V DC
- Current Rating: 15A
- Solenoid: 30A
- Cylinder Diameter: 1"
- Mounting Hole: 7/8"
- Terminals: 4 Screw
- Housing Material: Brass (traditional corrosion-resistant construction)
- Includes: Boot
- Push-to-Choke: Not included
Compatible Applications
- Outboard and inboard engines with conventional ignition systems requiring an Accessory position
- Classic, vintage, and premium marine helm panels where brass aesthetics are preferred
- Helm setups with chartplotters, VHF radios, or stereo systems requiring independent accessory power
- Marine dash panels with a 7/8" mounting hole accepting a 1" cylinder switch
- 12V DC circuits with loads up to 15A
- Direct replacement for worn or damaged OEM 4-position brass ignition switches
Parts Desk Insights
The MP39070 is the top-of-the-line choice in this ignition switch family — the right pick when you want a 4-position brass switch with a boot included for a classic or premium helm. The 1" cylinder diameter is unique in this family, so verify your panel cutout before ordering. If you need a 4-position switch but prefer a modern polyester housing, the Sierra MP39800 Polyester 4-Position Switch (1-1/8" cylinder, blade terminals) or the Sierra MP41040 Polyester 4-Position Screw Terminal Switch are the alternatives. If you only need a 3-position brass switch without an Accessory position, the Sierra MP39060 3-Position Conventional Brass Switch is the simpler fit at a lower price point.
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.