RV Generator Won't Start (or Won't Stay Running)

Onan and friends are reliable right up until the trip you need them. The classic pattern: it cranks, fires for three seconds, and dies — or won't crank at all after sitting since last season. The good news is that generator problems are overwhelmingly fuel and battery problems, and both are mobile-mechanic territory.

What it usually is

• Stale fuel / varnished carb after months parked (gas gensets)
• Fuel level below ¼ tank — most RV gensets refuse to run the tank dry on you
• Weak house battery: enough to click, not enough to start
• Clogged fuel filter or failing fuel pump on diesel units

While you wait — safe things to check

• Confirm fuel is above ¼ tank (the genset pickup sits high on purpose)
• Check the prime: hold prime 30–60s on Onans before cranking
• Look at the status light and count the blink code — tell chat the number
• If it clicks but won't crank, try after 30 min of engine charging

Get back to your trip

A mobile mechanic can diagnose fuel, filters, pumps, and batteries at your site or roadside — gas or diesel genset. Tell dispatch the make, the blink code, and where you are — mechanics bid back with rates and ETAs, and most generator calls end with the genset running the same day. Your boondocking week is salvageable.