166085902 A058T425 21 Ignition Coil for Cummins Onan RV Generator HGJAA HGJAB

This 21" Ignition Coil is a high-quality replacement ignition coil compatible with Cummins Onan RV Generators HGJAA and HGJAB, and matches OEM part numbers 166-0859-02 and A058T425.

Product Overview

This 21" ignition coil delivers a strong, consistent spark to maintain smooth ignition and reliable starts in your RV generator. Built as a direct replacement for worn coils on HGJAA and HGJAB models, the ignition coil restores proper timing and engine operation. It’s an essential service part for RV owners and technicians who need a dependable ignition coil without the dealership price.

Key Features & Performance

• 21-inch high-tension lead routes neatly to the spark plug on HGJAA and HGJAB generator sets
• High-output winding generates a hot spark for consistent combustion and clean starts
• Heat- and vibration-resistant epoxy encapsulation protects internal windings against harsh generator bay conditions
• Pre-installed spark plug boot and secure terminal ensure a firm, weatherproof connection
• Direct-fit mounting matches OEM bolt patterns—no drilling or bracket modification required

Fitment & Compatibility

• Cummins Onan RV Generator HGJAA
• Cummins Onan RV Generator HGJAB

Common Uses

• Replacing a failed or intermittent ignition coil on Cummins Onan RV generators
• Preventative maintenance to avoid no-start situations during camping trips
• Servicing aging ignition systems on high-hour HGJAA/HGJAB units
• Restoring reliable spark after moisture ingress or heat-related coil damage

Technical Specifications

• Part Number(s): 166-0859-02, A058T425
• Lead Length: 21 inches
• Type: Inductive ignition coil

Frequently Asked Questions

Q: Will this ignition coil work with my specific generator set? A: It is designed for Cummins Onan RV Generator models HGJAA and HGJAB and replaces OEM parts 166-0859-02 and A058T425. Always confirm your generator’s model and serial number against the part numbers to ensure correct fitment.

Q: What is the installation process for this coil? A: Disconnect the battery, remove the old coil and plug wire, mount the new 21" coil in the original position, and connect the high-tension lead. The direct-fit design requires no modifications and installs with basic hand tools.

Product appearance and specifications may vary slightly by batch. Compatibility may vary by serial number. Verify fitment before purchase.