Onan Run-Then-Stop – Safety Circuit or Fuel Issue

Generator starts then shuts down after a few seconds, no load applied, no clear code

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Faulty oil pressure switch opening prematurely, Blocked fuel filter causing starvation, Defective fuel shutoff solenoid dropping out, Loose safety circuit wiring

How to Fix / Troubleshooting

Safety first: Disable auto-start. Do not bypass safety switches permanently; only use temporary bypasses for testing if you are qualified.

  • Monitor fuel solenoid: Observe the fuel shutoff solenoid during start. If it opens then closes after a few seconds, check its power supply and coil.
  • Replace fuel filter: Install a new Onan fuel filter to eliminate restriction as a cause.
  • Check oil level and switch: Verify correct oil level. Inspect the oil pressure switch wiring. A faulty switch can signal low pressure even when pressure is normal; replace if suspected.
  • Inspect safety wiring: Trace the wiring between oil, temperature switches, and controller. Repair any loose or corroded connections.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Oil Pressure Switch
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements