CDI Electronics Remote Starter Test Harness 18-99561 for Mercruiser Engines, 2006 and Older

The CDI Electronics Remote Starter Test Harness, part number 18-99561, is a diagnostic tool built for bench-testing and remote-starting Mercruiser stern drive and inboard engines outside of the boat. It lets marine technicians and DIY boat owners crank and run an engine on a test stand or in the shop without needing the boat's factory ignition switch, wiring harness, or dash-mounted controls connected. This makes it a practical addition to any marine repair bay, allowing quick verification that an engine starts, runs, and responds correctly after service work such as carburetor rebuilds, ignition repairs, fuel pump replacement, or engine swaps.

Because it bypasses the boat's normal wiring, the harness speeds up troubleshooting by isolating the engine and its ignition system from the vessel's electrical system, helping technicians confirm whether a no-start or rough-running issue originates with the engine itself or with the boat's wiring and controls. It is designed for use with Mercruiser engines built through 2006, covering the older generation of Mercruiser ignition and starting systems.

Specifications

• Brand: CDI Electronics
• Manufacturer Part Number: 18-99561
• Product Type: Remote Starter Test Harness
• Compatible Engine Brand: Mercruiser
• Compatible Model Years: 2006 and older
• Weight: 1 pound
• UPC: 808282395506

Fitment

• Mercruiser engines, 2006 and older

Frequently Asked Questions

What is the CDI Electronics Remote Starter Test Harness 18-99561 used for? It is a diagnostic harness that lets you crank and start a Mercruiser engine outside the boat, bypassing the factory ignition switch and dash wiring so you can bench-test or troubleshoot the engine directly.

Which engines does part number 18-99561 fit? The 18-99561 test harness is designed for Mercruiser engines built in 2006 and older.

Does this harness work on newer Mercruiser engines built after 2006? No, the 18-99561 harness is intended for Mercruiser engines from 2006 and older; newer engines with different ignition and control wiring are not covered.

How much does the CDI Electronics 18-99561 test harness weigh? The remote starter test harness weighs 1 pound.

Do I need to disconnect my boat's dash wiring to use this harness? Yes, the purpose of the 18-99561 harness is to bypass the boat's normal ignition switch and dash controls so the engine can be started and run independently of the vessel's wiring.

Is this a genuine CDI Electronics part or an aftermarket copy? The 18-99561 is sold as a CDI Electronics branded remote starter test harness, not a generic aftermarket copy.

Can this harness help diagnose a no-start problem? Yes, by isolating the engine's starting and ignition circuits from the boat's wiring, the 18-99561 harness helps determine whether a no-start issue is caused by the engine or by the boat's electrical system.

Is the 18-99561 harness meant for professional mechanics only? It is commonly used by marine technicians in a shop setting, but boat owners comfortable with engine wiring can also use the CDI Electronics 18-99561 harness for bench testing.

What comes with the CDI Electronics remote starter test harness? The product is the 18-99561 remote starter test harness itself, used to crank and run a compatible Mercruiser engine outside the boat.

Will part number 18-99561 work on inboard and stern drive Mercruiser engines? The 18-99561 test harness is built for Mercruiser engines from 2006 and older; specific inboard versus stern drive distinctions are not specified beyond that engine coverage.