Sierra Ignition Coil Primary Wire Set for Mercury Mariner V6 Outboards - 18-99254

The Sierra 18-99254 Ignition Coil Primary Wire Set is a replacement primary wiring harness designed for Mercury Mariner V6 outboard engines. It carries the low-voltage primary current from the ignition system to the coil, and a worn, cracked, or corroded primary wire set is a common cause of misfires, hard starting, or intermittent ignition faults on V6 outboards. Replacing the primary wire set with a properly fitted harness like the 18-99254 restores a clean, secure electrical connection at the coil and helps the ignition system deliver consistent spark.

This wire set is built specifically for the V6 configuration used across Mercury and Mariner outboard engines, so it is sized and terminated to match the factory primary coil wiring layout rather than being a generic cut-to-fit wire. At 0.3 pounds, it is a light, compact part that is straightforward to route through existing engine wiring channels during a coil or ignition service.

Buyers servicing Mercury or Mariner V6 outboards use this primary wire set when replacing a damaged or deteriorated coil wire, during a full ignition tune-up, or when troubleshooting an intermittent spark condition traced back to the primary wiring.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99254
• Application: Mercury Mariner V6 outboard engines
• Component Type: Ignition coil primary wire set
• Weight: 0.3 pounds

Frequently Asked Questions

What engines does the Sierra 18-99254 ignition coil wire set fit? The Sierra 18-99254 is built for Mercury Mariner V6 outboard engines, matching the factory primary coil wiring layout used on that engine family.

What does this part actually do? It is a primary wire set that carries low-voltage current from the ignition system to the coil on Mercury Mariner V6 outboards, part number 18-99254.

How much does the 18-99254 wire set weigh? It weighs 0.3 pounds, making the Sierra 18-99254 primary wire set a lightweight, compact component to install.

When should I replace my ignition coil primary wire set? A cracked, corroded, or loose primary wire set is a common cause of misfires and hard starting; replacing it with the 18-99254 restores a secure connection to the coil on Mercury Mariner V6 outboards.

Is the 18-99254 a genuine Sierra part? Yes, 18-99254 is the Sierra manufacturer part number for this Mercury Mariner V6 ignition coil primary wire set.

Will this wire set fit a 4-cylinder or V8 Mercury outboard? No, the Sierra 18-99254 primary wire set is designed specifically for the V6 configuration of Mercury Mariner outboard engines.

Does the 18-99254 include the coil itself? No, the Sierra 18-99254 is the primary wire set only, used to connect the existing ignition coil in Mercury Mariner V6 outboards.

Can this wire set help with an intermittent spark problem? Yes, replacing a worn primary wire set such as the 18-99254 is a standard step when troubleshooting intermittent spark or ignition faults on Mercury Mariner V6 outboards.

Is installation of the 18-99254 something I can do myself? Because it is a direct-fit primary wire set for Mercury Mariner V6 outboards, the Sierra 18-99254 is routed through the existing wiring channels in place of the old wire during a standard coil or ignition service.

Does Sierra make both port and starboard versions of this wire set? The dossier for the Sierra 18-99254 does not distinguish a port or starboard version; it is listed as the primary wire set for the Mercury Mariner V6 engine configuration.