You’re ready for a weekend at the coast, you start your RV generator, and… nothing. Or maybe it starts but won’t stay running. Perhaps it runs but won’t power your appliances. Generator problems are among the most frustrating RV issues because they can derail your entire trip.
The good news? Many common RV generator problems have simple solutions you can handle yourself. This comprehensive guide from Leale’s RV—serving San Jose and Bay Area RV owners for over 15 years—covers everything from basic troubleshooting to knowing when professional repair is needed.
Whether you have an Onan, Cummins, Generac, or other generator brand, this guide will help you diagnose problems, understand what’s wrong, and get back to camping with reliable power.
Why RV Generators Fail (Especially in the Bay Area)
RV generators face unique challenges compared to home standby generators. They experience:
Vibration and movement during travel that loosens connections and components
Infrequent use causing fuel system problems (many Bay Area RVers only use generators seasonally)
Extreme temperature variations from California’s 40°F mornings to 100°F+ afternoons
Altitude changes going from sea level to mountain campgrounds
Dirty or stale fuel from sitting unused between trips
The #1 cause of generator failure: Lack of use. Generators that sit unused for months develop carburetor varnish, fuel system clogs, and starting problems.
Common RV Generator Problems & Solutions
Problem 1: Generator Won’t Start At All
Symptoms:
- No response when you push the start button
- No sound, no attempt to crank
- Dashboard shows no generator activity
Most Common Causes:
1. Dead or Low Battery Many RV owners don’t realize generators need the RV’s chassis battery (not house batteries) to start.
Solution:
- Check chassis battery voltage (should be 12.4V minimum)
- Charge battery if low
- Clean battery terminals if corroded
- Jump start if necessary
2. Tripped Circuit Breaker Generator circuit breakers protect the system and can trip from overload or short circuits.
Solution:
- Locate generator circuit breaker (often near generator or in main electrical panel)
- Reset breaker by pushing it firmly
- If it immediately trips again, you have an electrical problem requiring professional diagnosis
3. Low or No Fuel Seems obvious, but many start issues are simply empty LP tanks or fuel supply problems.
Solution:
- Check propane tank level (LP generators)
- Verify propane is turned on
- Check gas tank level (gas generators)
- Ensure fuel valve is open
4. Emergency Stop Switch Engaged Most RV generators have an emergency stop button that can accidentally get pressed.
Solution:
- Locate the emergency stop switch (usually on generator or nearby)
- Ensure it’s in the “run” position, not “stop”
- Reset if necessary
5. Oil Level Too Low Most modern RV generators have low-oil shutoff switches that prevent starting when oil is low.
Solution:
- Check generator oil level (pull dipstick)
- Add oil if low (use generator-specific oil)
- Wait a few minutes after adding oil before attempting to start
Problem 2: Generator Starts But Won’t Stay Running
Symptoms:
- Generator starts normally
- Runs for 5-30 seconds
- Dies and won’t restart immediately
Most Common Causes:
1. Carburetor Varnish/Clog (Most Common) Stale fuel creates varnish that clogs carburetor jets, especially in generators that sit unused.
Solution:
- Add fuel stabilizer to fresh fuel
- Let generator run for 20-30 minutes to cycle through system
- If problem persists, carburetor needs professional cleaning ($200-$400)
Prevention: Run generator under load for 30+ minutes monthly, even if not camping
2. Vapor Lock (Gas Generators) California heat can cause fuel to vaporize in fuel lines.
Solution:
- Let generator cool completely
- Pour cool water over fuel pump and lines
- Wait 30 minutes before attempting restart
- Consider heat shielding for fuel lines
3. Bad Gas or LP Contamination Old fuel (6+ months) or contaminated LP can cause starting then stalling.
Solution:
- Drain old fuel and replace with fresh
- For LP, ensure tank isn’t contaminated with oil or debris
- Add fuel stabilizer to fresh fuel
4. Faulty Fuel Pump Electric fuel pumps can fail, causing starvation after initial start.
Solution:
- Listen for fuel pump humming when starting
- If no sound, fuel pump may need replacement ($150-$350)
- Professional diagnosis recommended
Problem 3: Generator Runs But Produces No Power
Symptoms:
- Generator starts and runs smoothly
- Display shows generator running
- No power to outlets or appliances
- May show “no AC” or similar error
Most Common Causes:
1. Circuit Breakers Tripped Overloading causes breakers to trip, cutting power output.
Solution:
- Check all generator circuit breakers
- Reset any tripped breakers
- Reduce electrical load before restarting
2. Loss of Residual Magnetism Generators need residual magnetism in the rotor to produce electricity. Extended storage can cause loss.
Solution:
- “Flash” the generator to restore magnetism (requires specific procedure for your model)
- Professional service recommended ($100-$200)
3. Faulty Voltage Regulator The AVR (Automatic Voltage Regulator) controls output voltage. Failure means no usable power.
Solution:
- Professional testing required
- Replacement costs $200-$500 depending on model
4. Bad Rotor or Stator These core components can fail, especially in older generators.
Solution:
- Professional diagnosis required
- Repair costs $500-$1,500 depending on extent
- May be more cost-effective to replace generator if very old
Problem 4: Generator Runs Rough or Surges
Symptoms:
- Engine runs unevenly
- Power output fluctuates
- Lights flicker when using generator power
- Engine speeds up and slows down
Most Common Causes:
1. Dirty or Clogged Air Filter Restricted airflow causes rich fuel mixture and poor performance.
Solution:
- Remove air filter
- Clean foam filters with soap and water, re-oil lightly
- Replace paper filters ($10-$30)
- Check monthly during use season
2. Carburetor Needs Adjustment High altitude or temperature changes require carburetor adjustment.
Solution:
- Adjust idle speed screw (consult manual)
- Adjust fuel mixture if equipped
- Professional tuning recommended for complex adjustments ($100-$200)
3. Spark Plug Issues Fouled, worn, or incorrectly gapped spark plugs cause rough running.
Solution:
- Remove and inspect spark plug
- Clean or replace if fouled ($5-$15 per plug)
- Gap correctly per specifications
- Replace every 100-200 hours of operation
4. Governor Problems The governor controls engine speed. Failure causes surging.
Solution:
- Check governor linkage for damage or disconnection
- Professional repair typically required ($200-$400)
Problem 5: Generator Overheats or Shuts Down
Symptoms:
- Generator runs for a while then shuts down
- High temperature warning (if equipped)
- Generator hot to touch
- Won’t restart until cooled
Most Common Causes:
1. Blocked Cooling Airflow Generators need adequate ventilation. Blocked vents cause overheating.
Solution:
- Check all cooling vents for obstructions
- Clean debris from cooling fins
- Ensure generator compartment has adequate airflow
- Don’t run generator in enclosed spaces
2. Low Oil Level Low oil causes overheating and triggers automatic shutdown.
Solution:
- Check oil level when cool
- Add oil if low
- Check for leaks if oil drops frequently
3. Overloading Running too many appliances exceeds generator capacity.
Solution:
- Calculate total wattage of appliances
- Don’t exceed generator rated capacity
- Avoid starting multiple high-draw items simultaneously
- Common overload: Running two ACs + microwave + other items
4. Cooling Fan Failure Electric cooling fans can fail, causing rapid overheating.
Solution:
- Verify fan runs when generator operates
- Professional replacement if failed ($150-$300)
Problem 6: Excessive Noise or Vibration
Symptoms:
- Generator louder than normal
- Excessive shaking or vibration
- Rattling or knocking sounds
- Mounting bolts loosening
Most Common Causes:
1. Loose Mounting Bolts Road vibration loosens generator mounting over time.
Solution:
- Inspect all mounting bolts
- Tighten to proper torque specifications
- Check rubber isolation mounts for deterioration
- Replace worn mounts
2. Exhaust System Problems Cracked mufflers or loose exhaust pipes increase noise.
Solution:
- Inspect entire exhaust system
- Tighten loose connections
- Replace cracked or damaged components
- Professional welding may be needed
3. Worn Engine Mounts Rubber engine mounts deteriorate from heat and age.
Solution:
- Inspect mounts for cracks or compression
- Replace deteriorated mounts ($50-$150 per mount)
Generator Maintenance: Prevent Problems Before They Start
Monthly Maintenance (If Using Regularly)
Exercise Your Generator:
- Run for 30+ minutes under load
- Use at least 50% of rated capacity
- This prevents carburetor varnish and keeps systems lubricated
Check Levels:
- Oil level (add if needed)
- Coolant level (liquid-cooled models)
- Fuel supply
Visual Inspection:
- Look for leaks (oil, fuel, coolant)
- Check for loose wires or connections
- Inspect exhaust system
Every 3 Months (Even If Not Using)
Start and Run:
- Minimum 30-minute run under load
- Prevents fuel system problems
- Keeps internal components lubricated
Clean Air Filter:
- Remove and inspect
- Clean foam filters, replace paper filters
Check Battery:
- Ensure starting battery is charged
- Clean terminals if corroded
Annual Professional Service
Recommended service includes:
- Oil and filter change
- Spark plug replacement
- Fuel system cleaning
- Load bank testing
- Complete inspection
- Valve adjustment (if needed)
- Carburetor cleaning/rebuild
Cost: $200-$400 depending on generator size
Leale’s RV offers comprehensive generator service for all major brands.
DIY Troubleshooting Steps
Before Calling for Service, Try These:
Step 1: Check the Obvious
- ☐ Is there fuel?
- ☐ Is propane turned on (LP generators)?
- ☐ Is the battery charged?
- ☐ Are all breakers reset?
- ☐ Is oil at proper level?
- ☐ Is emergency stop switch in correct position?
Step 2: Basic Reset
- Turn generator off
- Wait 5 minutes
- Turn off all appliances/breakers
- Attempt restart with no load
- If successful, add load gradually
Step 3: Check for Codes
- Many generators display error codes
- Write down any codes shown
- Consult owner’s manual or search online
- Provide codes to technician if calling for service
Step 4: Document the Problem
- When did it last work correctly?
- How long has it been since last use?
- What happens when you try to start?
- Any unusual sounds, smells, or smoke?
- Any recent work done on RV or generator?
When to Call a Professional
DIY-Friendly Issues: ✅ Checking and adding fluids ✅ Replacing air filters ✅ Resetting breakers ✅ Basic visual inspections ✅ Spark plug replacement ✅ Tightening loose bolts
Requires Professional Service: 🔧 Carburetor cleaning or rebuilding 🔧 Fuel system repairs 🔧 Electrical system diagnostics 🔧 Rotor or stator replacement 🔧 Voltage regulator replacement 🔧 Engine internal repairs 🔧 Governor adjustment 🔧 Major component replacement
Call Leale’s RV immediately if:
- You smell gas or propane
- Generator produces smoke
- You see sparks or flames
- Generator makes grinding or knocking sounds
- Problem could affect safety
Generator Brands: Common Issues by Type
Onan Generators (Most Common in RVs)
Known issues:
- Carburetor problems from ethanol fuel
- Fuel pump failures
- Control board issues
- Starter solenoid problems
Maintenance tip: Run monthly even if not camping. Onan generators suffer most from disuse.
Cummins Onan Diesel
Common problems:
- Glow plug failures in cold weather
- Fuel injector issues
- Air in fuel system after running out
Bay Area advantage: Our mild climate reduces cold-start issues.
Generac Generators
Typical issues:
- Voltage regulator failures
- Starter problems
- Governor adjustment needed
Maintenance focus: Regular oil changes critical for longevity.
Honda Generators (Portable)
Common concerns:
- Carburetor varnish from ethanol
- Low oil shutdown sensor issues
- Recoil starter problems
Advantage: Generally very reliable with proper maintenance.
Generator Repair Costs (San Jose Area)
Common Repair Costs:
Basic Service:
- Oil change: $80-$150
- Spark plug replacement: $50-$100
- Air filter replacement: $30-$60
Common Repairs:
- Carburetor cleaning: $200-$400
- Fuel pump replacement: $150-$350
- Starter replacement: $200-$400
- Voltage regulator: $200-$500
- Control board: $300-$600
Major Repairs:
- Rotor/stator replacement: $500-$1,500
- Engine rebuild: $1,500-$3,000
- Complete generator replacement: $2,000-$6,000+
When to replace vs. repair:
- If repair exceeds 60% of replacement cost
- Generator is 15+ years old
- Multiple major components failing
- Frequent reliability issues
Choosing a New RV Generator
If replacement is needed, consider:
Size Requirements:
- Calculate total wattage needed
- Add 20% for startup surge
- Common sizes: 2,800W, 4,000W, 5,500W, 8,000W+
Fuel Type:
- LP/Propane: Uses same fuel as RV appliances, cleaner burning
- Gasoline: Often less expensive initially, fuel can go stale
- Diesel: Efficient, shares fuel with diesel motorhomes
Noise Level:
- Look for generators rated under 65 dB
- Quiet generators enhance camping experience
Features:
- Auto-start capability
- Remote start
- Digital displays
- Automatic load management
Popular Brands:
- Onan (Cummins) – Industry standard
- Generac – Good value
- Honda – Quiet, reliable (portable)
- Champion – Budget-friendly option
Generator Fuel: What You Need to Know
Gasoline Generators:
Fuel stability:
- Gas starts degrading after 30 days
- Always use fuel stabilizer
- Replace fuel if stored over 6 months
- Consider ethanol-free gas for storage
San Jose tip: California summer heat accelerates fuel degradation. Change more frequently.
LP/Propane Generators:
Advantages:
- Fuel doesn’t degrade
- Cleaner burning
- Uses RV’s propane supply
Considerations:
- Monitor propane levels
- Cold weather reduces LP pressure
- Tank refills readily available in Bay Area
Diesel Generators:
Benefits:
- Shares fuel with diesel motorhomes
- Very efficient
- Long-lasting fuel
Maintenance:
- Change fuel filters regularly
- Prevent water contamination
- Run frequently to prevent algae growth
Bay Area Generator Considerations
Altitude Adjustments:
Going from San Jose (sea level) to mountain camping requires:
- Carburetor may need adjustment above 5,000 feet
- Generator produces less power at altitude
- May run rougher until adjusted
Solution: Many modern generators auto-adjust, but older units may need manual tuning.
Temperature Impacts:
Summer heat (90-100°F+):
- Generators work harder
- Ensure adequate cooling airflow
- Watch for overheating
Cool mornings (40-50°F):
- Cold starts may be sluggish
- Choke may be needed (older models)
- Warm-up period recommended
Humidity:
Bay Area’s low humidity:
- Less moisture-related issues than humid climates
- Still use moisture absorbers if stored near coast
- Prevents electrical corrosion
Emergency Generator Alternatives
If your generator fails while camping:
1. Portable Generator:
- Keep a small backup portable unit
- Honda EU2200i is popular (super quiet)
- 2,000W handles essentials
2. Solar Power:
- Portable solar panels + battery
- Can power lights, fans, charging
- Won’t run A/C
3. Shore Power:
- Many campgrounds offer hookups
- Request powered site as backup plan
4. Inverter Power:
- Use house batteries with inverter
- Limited duration but covers essentials
- Recharge when driving
Frequently Asked Questions
Q: How often should I run my RV generator? A: Minimum once per month for 30+ minutes under load. More frequently is better. This prevents fuel system problems and keeps components lubricated.
Q: Why won’t my generator power my air conditioner? A: Common reasons: Overloaded circuit, low voltage output, or AC draws too much power for generator capacity. A 13,500 BTU AC typically needs 2,800-3,500W to start.
Q: How long should an RV generator last? A: With proper maintenance, 10,000-15,000 hours (roughly 15-20 years of typical RV use). Neglected generators may fail in 5-7 years.
Q: Can I run my generator while driving? A: Most RV generators can run while driving. Check your manual. Many RVers do this to keep coach cool and refrigerator running.
Q: Is it normal for my generator to smoke when first starting? A: Brief white smoke when starting after storage is normal (oil in combustion chamber). Black smoke or continuous smoking indicates problems.
Q: How much does professional generator service cost in San Jose? A: Basic service (oil change, filter, inspection): $150-$250. Comprehensive annual service: $200-$400. Repairs vary by issue.
Q: Should I use my generator in San Jose residential areas? A: Check local noise ordinances. Many neighborhoods restrict generator use to daytime hours. Be considerate of neighbors.
Leale’s RV Generator Services
Why San Jose RV owners trust Leale’s for generator service:
✅ All major brands serviced – Onan, Cummins, Generac, Honda, Champion ✅ Experienced technicians – 15+ years RV generator expertise
✅ Complete diagnostics – Advanced equipment finds problems fast ✅ Honest recommendations – Repair vs. replace guidance you can trust ✅ Convenient location – Easy access from throughout Bay Area ✅ Fair pricing – Transparent estimates, no surprises ✅ Quality parts – OEM or quality aftermarket components
Schedule Generator Service Today
Don’t wait for your generator to fail on your next trip. Preventive maintenance and professional service keep your generator reliable when you need it most.
📞 Call Leale’s RV: (408) 286-5353
🗓️ Schedule Generator Service →
📍 581 Race Street, San Jose, CA 95126
Our comprehensive generator service includes:
- Complete inspection and diagnostics
- Oil and filter change
- Spark plug service
- Air filter replacement
- Fuel system check
- Load testing
- Written report with recommendations
Special: Free generator inspection with any RV service appointment!
Don’t let generator problems ruin your next camping adventure. Trust Leale’s RV to keep your power systems reliable and road-ready!
Leale’s RV | 581 Race Street, San Jose, CA 95126 | (408) 286-5353
Serving San Jose, Santa Clara, Sunnyvale, Campbell, Los Gatos, Mountain View, and the entire Bay Area