Aftermarket Switch Box / CDI Power Pack for Mercury & Force Outboards – Replaces 18-5775, 332-7778A12, 332-7778A9 and Other Listed Numbers
Aftermarket Switch Box / CDI Power Pack for Mercury & Force Outboards – Replaces 18-5775, 332-7778A12, 332-7778A9 and Other Listed Numbers is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
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Aftermarket Switch Box / CDI Power Pack for Mercury & Force Out...
Aftermarket Switch Box / CDI Power Pack for Mercury & Force Outboards – Replaces 18-5775, 332-7778A12, 332-7778A9 and Other Listed Numbers is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket switch box, also called a CDI power pack, is a replacement ignition component for selected Mercury and Force outboards using the specified ignition system. It is listed for a range of 3-cylinder and 6-cylinder applications, including the Mercury models and serial-number ranges shown below.
The unit is listed as an interchange for Sierra 18-5775 and for the Mercury and Force manufacturer part numbers shown in the cross-reference table. The exact application depends on engine model, cylinder configuration, ignition system and serial number.
- Replacement switch box for compatible Mercury and Force outboard ignition systems.
- Designed to replace the original component when the listed part number and serial-number range match.
- Use the engine-specific compatibility information below before ordering; similar-looking switch boxes are not necessarily interchangeable.
Part Number Matrix
These references are included as replacement and interchange identifiers. Confirm the number on your original unit and your engine serial number before installation.
| Brand | Part Number |
|---|---|
| Sierra | 18-5775 |
| Mercury Marine | 332-7778A12 |
| Mercury Marine | 332-7778A9 |
| Mercury Marine | 332-7778A6 |
| Mercury Marine | 332-7778A3 |
| Mercury Marine | 332-5524A1 |
| Mercury Marine | 332-7778A1 |
| Mercury Marine | 332-7778A7 |
| Mercury Marine | F749301 |
| Mercury Marine | F7778A9 |
| Chrysler Force | 332-7778A12 |
Engine & Model Compatibility
Confirm the complete engine model, cylinder configuration and serial-number range before ordering. The same horsepower may use different switch boxes depending on the engine version and serial number.
| 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
- Aftermarket switch box / CDI power pack
- Application
- Selected Mercury and Force outboard ignition systems
- Engine Configuration
- Selected 3-cylinder and 6-cylinder applications
- Installation
- Replacement installation using the original mounting location and engine-specific wiring arrangement
- Primary Reference
- Sierra 18-5775
- OEM Reference
- Mercury Marine 332-7778A12 and other numbers listed in the part-number matrix
- Fitment Verification
- Match the original part number, engine model, cylinder configuration and serial-number range
What’s in the Box
- 1 x Aftermarket switch box / CDI power pack
Installation Notes
- Disconnect the battery and follow the engine manufacturer’s electrical safety procedures.
- Locate the existing switch box and document every wire connection before removal.
- Disconnect the wires carefully and label them if necessary.
- Remove the original unit from its mounting location.
- Inspect the mounting area, terminals and wiring for corrosion, damage or loose connections.
- Install the replacement switch box using the original mounting hardware where appropriate.
- Reconnect each wire according to the engine wiring diagram and the original connection layout.
- Before starting the engine, verify that all terminals are secure and that the installation matches the correct model and serial-number application.
- Test the ignition system in a safe, well-ventilated area. Professional installation is recommended when testing or servicing marine ignition components.
Troubleshooting & FAQ
How do I know if my switch box has failed?
Possible symptoms include no spark on one or more cylinders, intermittent spark, misfiring, hard starting or an engine that will not start. Proper diagnosis normally requires an appropriate marine ignition test procedure and may require a DVA meter. Test the stator, trigger, ignition coils, wiring and grounds before replacing the switch box.
Will this fit my specific engine year?
Fitment is determined by engine model, cylinder configuration, ignition system and serial number rather than year alone. Match your engine to the compatibility table and compare the part number on the original switch box.
What is an ADI ignition system?
ADI, or Alternator Discharge Ignition, is an ignition arrangement used on many older Mercury and Force outboards. This replacement should only be used when the engine’s ignition system and application match the listed references.
Is this a plug-and-play installation?
It is intended as a replacement for the specified applications, but it is not universal. Wiring, mounting and timing-related checks must follow the engine’s service information. Verify every connection before applying power.
What is the difference between a 3-cylinder and 6-cylinder application?
The required switch box depends on the ignition-system design and engine configuration. Do not substitute between 3-cylinder and 6-cylinder engines unless the exact part number and application data confirm compatibility.
Can I use this with a different ignition system?
No. Use this component only with the ignition system and engine applications identified in the listing. Installing it on an incompatible ignition system may cause improper operation or electrical damage.
Is this an OEM component?
No. This listing is for an aftermarket replacement. Mercury, Force, Sierra and other manufacturer names and part numbers are used only to identify application and interchange references.
Shipping speed & cost
Shipping availability, delivery time and cost are shown at checkout and may vary by destination and service level.
Warranty & returns
Warranty and return coverage follow the seller’s current policy. Review the applicable policy before installation, and retain the original part until fitment has been confirmed.
Safety & Important Info
- Verify the original part number, engine model, cylinder configuration and complete serial-number range before purchase.
- Do not rely on horsepower alone to confirm compatibility.
- Disconnect the battery before servicing ignition wiring.
- Do not operate the engine in an enclosed or poorly ventilated area.
- Professional installation and diagnostic testing are recommended for marine ignition systems.
About Sea Sierra
- Marine replacement parts selected for application-specific fitment.
- Clear interchange and compatibility information to support accurate ordering.
- Customer support for product and installation questions.
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