Your generator not starting always happens 30 minutes before you need it. Before you call for help, work through this checklist — most no-start conditions come down to a handful of causes you can fix on the spot.
Your RV generator not starting is one of those problems that always happens 30 minutes before you actually need it. You're parked somewhere without hookups, it's getting warm, and the generator that ran fine six months ago is doing absolutely nothing. Before you call for help, work through this checklist — most generator no-start conditions come down to a handful of causes, and a few of them you can fix on the spot.
Start With the Obvious (Most People Skip This)
- Check the main circuit breaker on the generator itself — there's usually a reset button or breaker that trips on overload. It's often on the side or rear of the unit.
- Confirm the generator isn't in "remote start only" mode — some units have a control panel switch that disables the manual start button.
- Check for any fault indicators or error codes on the display panel if your unit has one.
- Make sure the RV's main battery disconnect isn't off — some generators draw from the coach batteries for the starter circuit.
Fuel and Oil — The Two That Get Everyone
These two account for the majority of generator no-start calls we go out on:
Low or stale fuel
If your generator runs off the RV's main fuel tank, most units have a cutoff that prevents them from starting when the tank is below one quarter. You may have enough fuel to drive but not enough to run the generator. Fill up first. If the fuel has been sitting for more than 60–90 days, stale fuel is also a suspect — ethanol-blended gasoline degrades and gums up carburetors fast.
Low oil — the oil pressure shutoff
Every modern RV generator has a low oil pressure shutoff that prevents the engine from starting when oil is low. This is a feature, not a fault. Check the dipstick before you assume anything is wrong electrically. A generator that cranks but won't fire is often telling you the oil is low. Check it, add oil if needed, and try again.
Exercise your generator monthly
A generator that sits unused for months is a generator that will fail when you need it. Run it under load for at least 2 hours every month — turn on the AC or a couple of high-draw appliances. This keeps the fuel system from gumming up, circulates the oil, and keeps seals from drying out. A generator that gets exercised regularly starts every time. One that sits for 8 months between camping trips is a diagnostic appointment waiting to happen.
Spark, Carburetor, and Starting Circuit
If fuel and oil are both fine and it still won't start:
- Spark plug — pull it and inspect. A fouled, cracked, or worn plug is a common cause of hard starts and no-starts, especially on generators that don't get regular use. Plugs are cheap. Replace it if there's any doubt.
- Carburetor — stale fuel leaves behind varnish deposits that clog the tiny fuel passages in the carb. Symptoms: cranks fine, won't fire, or starts and immediately dies. A carb cleaning or rebuild is the fix. On generators that sat over winter without fuel stabilizer, this is extremely common.
- Choke — on manual-choke generators, the choke needs to be fully closed when starting cold. If it's stuck open, the engine won't have the rich fuel mixture it needs to fire cold.
- Starter solenoid — if you hear a click when you hit start but nothing else happens, the starter solenoid may have failed. It's the relay between the battery and the starter motor.
Generator Starts but Shuts Off
A generator that fires and then dies within seconds or minutes is a different problem:
- Low oil shutoff triggering after startup — oil was borderline on the dipstick but pressure dropped once it was running. Add oil.
- Overloading immediately — if the AC kicks on automatically when the generator starts and the load trips it, the generator is undersized for that load or something in the AC is drawing too much on startup.
- Choke issue — if it runs fine when choked but dies when the choke opens, the carburetor has a fuel delivery problem.
- Cooling — if it runs for 5–10 minutes then shuts off, the cooling fins may be blocked with debris or the unit is running in an enclosed space without adequate airflow.
Common Question
How often should I service my RV generator?
Every 100–150 hours of operation, or once a year minimum — whichever comes first. Service includes an oil and filter change, spark plug inspection or replacement, air filter cleaning or replacement, and fuel system inspection. If you use it heavily during camping season, check the oil level every 8 hours of operation. A well-maintained generator runs for decades. A neglected one needs a rebuild or replacement in 5–7 years.
Most generator no-starts are solved with fresh oil, fresh fuel, a new spark plug, or a carb cleaning — none of those require a service call if you're comfortable doing basic maintenance. But if you've worked through all of the above and it still won't run, the issue is likely electrical or internal and it's time to call us out. We'd rather come diagnose it at your campsite than have you tow it somewhere and wait three weeks.
BossBros RV Team
Redding, CA