Switch Box / Power Pack – Fits Mercury & Force 3 & 6 Cyl 50-275 HP (Replaces 332-7778A12, 332-7778A9, 332-7778A6)

$183.99 $294.00

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Switch Box / Power Pack – Fits Mercury & Force 3 & 6 Cyl 50-275 HP (Replaces 332-7778A12, 332-7778A9, 332-7778A6) is backordered and will ship as soon as it is back in stock.

Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Switch Box / Power Pack is engineered for Mercury & Force 3 & 6 cylinder outboards from 50-275 HP, primarily serving models from the 1980s to 2000s equipped with an Alternator Discharge Ignition (ADI) system. It ensures reliable spark and engine timing for consistent performance.

It serves as a direct interchange for Sierra 18-5775, CDI 114-7778, and several Mercury part numbers including 332-7778A12, 332-7778A9, and 332-7778A6.

Designed for direct bolt-on installation, mounting in the OEM location.
Constructed with a fully epoxy-sealed housing for marine-grade durability against moisture and vibration.
Features color-matched wiring to OEM specifications for a straightforward setup.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Sierra	18-5775
CDI Electronics	114-7778
Mercury	332-7778A12
Mercury	332-7778A9
Mercury	332-7778A6
Mercury	332-7778A3
Mercury	332-5524A1
Mercury	332-7778A1
Mercury	332-7778A7
Mercury	F749301
Mercury	F7778A9
Mallory Marine	9-25100

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This component is designed for the following Mercury & Force models. Verify your engine's serial number falls within the specified range.

Model (HP)	Beginning Serial No.	Ending Serial No.	OEM Part No.
50/60 (3 cyl)	6428681	D000749	332-7778A12
65/70	4382057	& UP	332-7778A12
70/75 (3 cyl)	C272000	D283221	332-7778A12
80 (3 cyl)	A996142	C221999	332-7778A12
90 (6 cyl)	5299506	& UP	332-7778A12
90 (3 cyl)	A996142	D283221	332-7778A12
90 (Sport Jet Powerhead)	E023150	E095087	332-7778A12
105 (Jet)	D082000	G303045	332-7778A12
115 (6 cyl)	5314656	& UP	332-7778A12
V-135	A904646	& UP	332-7778A12
140	5327663	& UP	332-7778A12
140 (Jet)	D082000	G960499	332-7778A12
V-150	4868998	G960499	332-7778A12
V-150 XR2	6616991	A904645	332-7778A12
XR4, Magnum II	B242885	D819999	332-7778A12
V-150 XR6	D820000	G960499	332-7778A12
V-175, EFI, XR1	4301235	G960499	332-7778A12
V-200, XR1	4839034	G960499	332-7778A12
V-220	B117316	& UP	332-7778A12
V-225	5628028	& UP	332-7778A12

Technical Specs

Product Type: Switch Box / CDI Power Pack
Installation: Direct bolt-on replacement
Application: ADI Ignition System
Compatibility: 3 & 6 cylinder Mercury/Force outboards
Engine Range: 50-275 HP
Channels: Multiple (supports 3 & 6 cylinder engines)
Housing Material: Epoxy-sealed unit
Weight: 1.02 lbs (0.46 kg)
Mounting: Direct OEM location
Wiring: Color-matched to OEM specifications
Warranty: Limited Lifetime (Sierra brand)
Other Technical Attributes: Enhanced spark efficiency, marine-grade durability

What’s in the Box

1 x Switch Box CDI Power Pack (332-7778A12)

Installation Notes

Disconnect the battery terminals to prevent electrical shorts.
Locate the existing switch box on the engine block. Note the wiring connections.
Carefully disconnect all wires leading to the switch box, labeling them if necessary.
Unbolt and remove the old unit from its mounting points.
Clean the mounting surface to ensure a solid connection and proper grounding.
Mount the new switch box, securing it with the original hardware.
Reconnect the wires according to the OEM color code, ensuring all connections are tight.
Reconnect the battery and test the engine's ignition system in a safe, well-ventilated area.

Troubleshooting & FAQ

How do I know if my switch box has failed?

Common symptoms of a faulty switch box include no spark on one or more cylinders, intermittent spark, engine misfiring at high RPMs, or a complete failure to start. A DVA (Direct Voltage Adapter) meter is often required to test the output accurately.

Will this fit my specific engine year?

This part fits a wide range of models across several decades. The most reliable way to confirm fitment is by matching your engine's serial number to the ranges provided in the compatibility table or by matching the part number stamped on your original switch box.

What is an ADI ignition system?

ADI (Alternator Discharge Ignition) is a type of ignition system used on many Mercury and Force outboards. It uses the alternator's output to charge the ignition system, as opposed to a stator-driven CDI system. This switch box is specifically designed for ADI systems.

Is this a simple plug-and-play installation?

Yes, it is designed as a direct replacement. It uses the same mounting points and color-coded wires as the OEM part, making installation straightforward for those with basic mechanical skills. However, professional installation is always recommended.

What is the difference between a 3-cylinder and 6-cylinder switch box?

This particular unit is versatile and designed to work with both 3 and 6-cylinder engines that use the specified ADI ignition system. It has the necessary internal circuitry to correctly manage ignition timing for either configuration.

Can I use this with a different ignition system?

No. This switch box is only compatible with the ADI (Alternator Discharge Ignition) systems specified in the application list. Using it on other ignition types can cause damage to the part and the engine's electrical system.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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