Sierra 18-99230 Switch Box | Mercury/Mariner 15/20/25 HP
Sierra 18-99230 Switch Box | Mercury/Mariner 15/20/25 HP
Sierra
Low Stock: 1 left
Couldn't load pickup availability
Sierra 18-99230 — Switch Box | Mercury/Mariner 15, 20, & 25 HP
Sierra 18-99230 (formerly CDI Electronics 114-4952A30) is a high performance replacement ignition switch box for Mercury and Mariner 2-cylinder outboard engines. Fits Mercury/Mariner 15 HP model XD/S15 (1994-1996, serial 0G044365-0G437999), 20 HP (1994-1996, serial 0G044027-0G437999; and 1997-1998, serial 0G438000-0G760299), and 25 HP model Jet 20 (1994-1997, serial 0G044027-0G437999) 2-cylinder outboards. Replaces Mercury 18495A9, 18495A14, 18495A16, 18495A17, 18495A20, 18495A21, and 18495A30.
Confirm Fitment Before Ordering
Not sure if this switch box fits your outboard? Give us your engine model, HP, and serial number and we'll confirm it for you before you order — by email, text, or live chat.
Part Specifications
- Sierra Part Number: 18-99230 (CDI 114-4952A30)
- Type: Ignition switch box
- Application: Mercury/Mariner 15 HP XD/S15 (1994-1996, SN 0G044365-0G437999); 20 HP (1994-1996, SN 0G044027-0G437999; 1997-1998, SN 0G438000-0G760299); 25 HP Jet 20 (1994-1997, SN 0G044027-0G437999) 2-cylinder outboards
- Replaces: Mercury 18495A9, 18495A14, 18495A16, 18495A17, 18495A20, 18495A21, 18495A30
Additional Information
- Vendor: Sierra International
- Part Number: 18-99230
- OEM Cross-Reference: CDI 114-4952A30; replaces Mercury 18495A9, 18495A14, 18495A16, 18495A17, 18495A20, 18495A21, 18495A30
Installation Notes
Install following the applicable Mercury/Mariner outboard service manual for your engine model, HP, and serial number range.
Frequently Asked Questions
Q: How do I confirm this switch box fits my outboard?
A: Send us your Mercury/Mariner engine model, HP, and serial number and we'll confirm 18-99230 is the correct switch box for your engine — by email, text, or live chat.
Q: Why does my engine's serial number matter for this part?
A: Mercury changed switch box requirements across different serial number ranges within the same HP and model year, so the serial number confirms which switch box your specific engine needs.
Q: What are signs my switch box is failing?
A: Common symptoms include hard starting, misfiring, stalling, or a complete no-spark condition, especially when the engine is warm.
Q: Is this the same as the CDI 114-4952A30?
A: Yes, Sierra 18-99230 and CDI 114-4952A30 are the same switch box; Sierra is the current supplying part number.
Q: What Mercury part numbers does this replace?
A: It replaces Mercury 18495A9, 18495A14, 18495A16, 18495A17, 18495A20, 18495A21, and 18495A30.
! Compatibility references are provided for informational purposes only and do not constitute a fitment guarantee. Part numbers, application listings, and "replaces" cross-references are based on manufacturer data and are intended as a starting point for identification — not a guarantee of fit for your specific engine, hull, or installation.
Buyer is solely responsible for verifying compatibility with their engine model, serial number, model year, and trim configuration before purchase. If you are unsure whether this part fits your application, contact MacombMarineParts.com before you buy — we're available via text, email, or online chat to help verify compatibility for your specific application.
MacombMarineParts.com is not liable for parts ordered based on assumed fitment. Returns due to buyer-selected incorrect fitment are subject to our standard return and restocking fee policies.