Your Onan 5500 generator's fuel pump chatter and dual light illumination indicates a control board communication error triggered by the remote harness connection. This comprehensive guide covers diagnosis, repair steps, and prevention strategies for all common Onan 5500 issues.
The RC7-GS inverter charger can properly charge 105Ah AGM batteries using the 125Ah setting, as AGM charging is voltage-based, not capacity-dependent. Generator start issues typically stem from wiring problems or incorrect DIP switch configurations.
Your 1993 American Eagle's Onan generator producing only 12-15 volts indicates a faulty rectifier bridge (part CR21) or suppressor (part RV21). The correct replacement parts are 305-0696 for the rectifier bridge and 305-0703 for the suppressor.
Keep your RV generator running reliably with this comprehensive maintenance and troubleshooting guide for Onan, Generac, and Cummins units.
Onan fault codes display via LED blinks or digital display. Common codes include 12-overspeed, 13-low oil, 14-high temp. Consult model-specific service manual for complete code list. Persistent codes may require professional diagnosis.
Generator surging is typically caused by a dirty carburetor, fuel system issues, or governor problems. Start by cleaning the carburetor and air filter, then check fuel quality and governor linkage.
The Onan 5500 can be tuned up with quality aftermarket parts when OEM parts are unavailable. Use NGK 3432 spark plugs, Wix 57358 oil filter (not 57398), and zinc-containing oils like Rotella T6 for optimal performance.
Code 14 is overspeed but your real issue is carburetor gummed from sitting. Choke mechanism needs cleaning to operate automatically. Clean carburetor thoroughly - jets and choke linkage. Use fresh fuel and add stabilizer to prevent future issues.
Year of storage without stabilizer causes carburetor varnish. Carburetor needs thorough cleaning or rebuild - soaking, jet cleaning, new gaskets. Running rough and stalling under load are classic symptoms of blocked jets from old fuel residue.
After running out of gas, air is in fuel system. Hold start switch longer (15-30 seconds) to purge air. May take several attempts. Check oil level is correct after change.
Worn Onan 10KW generator mounts cause vibration and noise. Replace with OEM parts from Cummins dealer. Most owners have shops do this due to generator weight and access challenges.
Some Cummins dealers limit service on older equipment but this is not universal. Call other dealers, use independent diesel shops, or find mobile RV mechanics. Many specialists focus on older Onan generator repair. Parts still generally available.
Shutting down under load after rebuild suggests carburetor still not delivering enough fuel or governor sticking. Watch governor arm movement during load test. Try gradual load increase to find threshold. Check fuel pump output if equipped.
Cummins in RVs are diesel engines or Onan generators. Gas chassis use Ford or GM. Cummins diesel and Onan generators need regular maintenance.
Your Onan 7000 generator fuel pump is receiving only 9V instead of the required 12V, causing starting issues. This voltage drop is typically caused by corroded connections, faulty control board, or wiring problems in the fuel pump circuit.