RV Generator Repair in Iowa

RV Generator Repair in Iowa — Onan, Generac, Cummins, Kohler

The onboard generator is what turns your RV into an actual mobile home rather than a tent with wheels — and when it quits, the coach loses AC, microwave, coffee maker, and half the reason you own it. Ames Hydraulics does rv generator repair on the four major RV genset brands: Onan (Cummins-Onan) Marquis Gold, QG, and Quiet Diesel; Generac Nomad and Guardian mobile; Cummins Onan-branded RV gensets; and Kohler mobile. We’re not an RV shop — we’re a mechanical and hydraulic shop that also does industrial generator work — and RV gensets are basically small industrial generators packaged for coach installation. Same repair discipline, tighter package.

What Fails On RV Generators

Common rv generator repair jobs, ordered by frequency:

• Won’t start / cranks but won’t fire. Fuel delivery is the top suspect — clogged fuel filter, failed fuel pump, contaminated fuel from a coach that sat all winter, air in the fuel system. Diagnostic and cleanup.
• Starts but shuts down within seconds. Usually low oil pressure switch, coolant temp switch, or overload trip. Check oil, check coolant, check load.
• Runs but no output. AVR (automatic voltage regulator), stator windings, or brushless generator field. Deeper electrical diagnostic.
• Runs rough or surges under load. Governor issue, dirty carburetor on older gasoline units, fuel-pressure problem on diesel units.
• Overheating. Radiator/cooling airflow blocked, water pump failure on liquid-cooled units, fan issue.
• Excessive vibration or noise. Engine mount failure, exhaust hanger cracked, bearing wear.
• Won’t crank at all. Battery, starter, or start-circuit issue.
• Oil leak. Front seal, rear main, valve cover, or pan gasket — genset engines have the same failure modes as small industrial engines.

RV Generator Brands And Model Notes

Onan (Cummins-Onan): The dominant RV genset. Marquis Gold (older gasoline), QG (current gasoline and diesel), and Quiet Diesel are the common models we see. Onan gensets are well-engineered but need routine maintenance — oil, filters, spark plugs (gasoline), fuel filters (diesel), and cooling maintenance. Parts availability is excellent through Cummins channels.

Generac Nomad and Guardian mobile: Second-most-common RV genset brand. Similar architecture to Onan — gasoline and diesel options, air-cooled and liquid-cooled variants. Parts available through Generac dealer network and aftermarket.

Cummins Onan-branded RV gensets: Larger coaches (motorhomes, Class A rigs) often carry proper Cummins-Onan diesel gensets rather than the smaller QG series. Same repair discipline; diesel-specific fuel and injection system knowledge required.

Kohler mobile: Less common than Onan or Generac but present in some higher-end coaches. Solid units; parts and service network smaller than Onan.

Honest Scope On RV Generator Repair

What we handle: fuel system (pumps, filters, injectors, carburetor on older units), ignition (points and electronic on older units), mechanical (cooling, oil, valves, bearings), electrical output (AVR, stator, field — to a diagnostic depth), and structural (mount cracks, exhaust hangers). What we don’t handle: 12V DC coach wiring, inverter/converter/BMS work on the coach house electrical, propane appliance service, and deep genset control-board electronics that require factory Cummins/Generac/Kohler diagnostic tools. Where dealer service is right: warranty, deep control-board diagnostics, and complete engine replacements on newer sealed units.

Iowa RV Generator Duty-Cycle Notes

Iowa RVs typically see seasonal use — heavy May-October, occasional winter, and long storage periods. That’s hard on rv generator repair economics because sitting is the enemy of small engines. Common Iowa-specific failures: fuel contamination from ethanol degradation over a winter of storage (this is huge on gasoline gensets), varnished carburetor jets on older Onan Marquis Gold units, and rodent damage to wiring in stored coaches. Owners who add fuel stabilizer before storage and start the generator monthly through the winter avoid 80% of these problems. When you bring us a generator that won’t start in the spring, we’ll ask whether the coach was stored with treated fuel — the answer usually tells us where to look first.

RV Generator Repair Cost Ranges

• Diagnostic and quote on unclear failure: 1–2 shop hours
• Fuel system cleanup and filter service: $200–$500
• Carburetor rebuild on older gasoline Onan: $300–$700
• Fuel pump replacement: $250–$650
• Full tune-up (plugs, filters, oil, valve adjust): $250–$600
• Water pump replacement (liquid-cooled): $400–$1,200
• Starter motor replacement: $250–$600
• AVR / voltage regulator replacement: $300–$900
• Major mechanical repair (bearings, seals, valve work): $600–$3,500

Coordinating RV Generator Repair With Other RV Work

Many owners bring us rv generator repair alongside hydraulic leveling or slide-out work — one visit, whole coach freshened up. It saves scheduling and towing. See RV & camper repair hub, RV leveling, and RV slide-out repair for the hydraulic side. Also see our commercial generator repair and truck generator repair pages — the same technical discipline scales up to industrial standby units.

Related Ames Hydraulics Pages

• RV & Camper Repair (hub)
• Commercial Generator Repair
• Truck Generator Repair
• Generator Installation
• Fuel Polishing & Testing

RV Generator Repair FAQ

My Onan won’t start after winter storage. Almost always fuel-related — degraded ethanol gas, clogged filter, gummed carburetor. Bring it in for cleanup.

Do you work on all RV generator brands? Onan, Generac, Cummins, Kohler — yes. Very rare brands (older Powertech, small Chinese-market units) — call and describe.

Warranty work on my new Onan? Use a Cummins-authorized RV service center for warranty. Out-of-warranty, we’re the alternative.

Can you fix a generator without removing it from the coach? Depends on the repair. Simple work yes; major mechanical often needs the genset out for bench work.

Diesel or gasoline — does it matter? We handle both. Diesel gensets need fuel-system knowledge (which we have); gasoline gensets need carburetor/ignition discipline (which we have).

Get RV Generator Repair Scheduled

Call or text 515-292-2599. Ames Hydraulics, 3223 South Duff Avenue, Ames, Iowa. Independent rv generator repair on Onan, Generac, Cummins, and Kohler onboard gensets — the mechanical shop that also handles your leveling, slide-outs, and aluminum welding in one visit.