# Generator Service and Repair for Eastvale, California > Onboard generator service, fuel and ignition work, control board diagnosis and load bank testing so the set carries its rated load under heat. Source: https://ocrv.info/services/electrical-power-and-generators/generator-service-and-repair Generator service and repair covers onboard sets from Onan, Cummins and comparable manufacturers: routine service, fuel system and carburetor work, brush and slip ring replacement, control board diagnosis, exhaust and mounting repair, and load bank verification. OCRV Center performs all generator work in shop at its Yorba Linda facility. ## Pricing Range $400 to $8,500+. Labor band 2 to 35 hours. Performed in shop at 23281 La Palma Ave, Yorba Linda, CA 92887. Onboard generators fail from disuse far more often than from wear. A set that runs two hours a year develops varnish in the carburetor bowl, stale fuel in the pickup line, dry gaskets, oxidized brush contact surfaces and seized governor linkage. The owner discovers all of it on the first hot afternoon when the coach is parked away from shore power. Exercising the set under load once a month prevents most of what brings generators into this bay. Diagnosis splits into two branches immediately. Either the set will not start and run, which points at fuel, ignition, compression and starting circuit, or it starts and runs but will not carry load, which points at the generator end: brushes, slip rings, rotor and stator windings, capacitor, voltage regulation and the control board. Those branches share almost no parts, and confusing them is how owners end up paying for a carburetor when the problem was a set of brushes. Every set that leaves here gets load banked. Starting a generator in the bay and hearing it idle smoothly proves nothing about whether it will hold two roof air units at one hundred degrees in the Inland Empire. Load banking applies a real resistive load in steps, watches voltage and frequency stability at each level, monitors exhaust temperature and confirms that the set holds output as it heats up rather than falling off after ten minutes. ## What brings this in - Cranks strongly but never fires - Starts then shuts down after thirty seconds - Runs smoothly but produces no output voltage - Voltage sags whenever the second air conditioner starts - Surging or hunting engine speed at steady load - Black smoke and rough running under load - Exhaust soot or rattling from under the coach - Control board displaying a fault code with no obvious cause ## The Set That Will Not Start Cranking without firing is nearly always fuel on a gasoline set. The pickup tube in the fuel tank sits above the main pickup by design, so the coach can run out of generator fuel while still showing a quarter tank. Beyond that, the fuel pump, the filter, the solenoid on the carburetor and the bowl itself all accumulate deposits. Varnish in the main jet is extremely common on sets that sat through a season with untreated fuel in them. Diesel sets fail differently. Air in the fuel system after a filter change, a lift pump that has lost prime, injectors with poor spray pattern and glow plug circuits that no longer preheat all present as extended cranking. We check fuel pressure and return flow, bleed the system properly, and verify the preheat circuit draws current before condemning anything expensive. Compression testing follows if the fuel side checks out and the set still refuses to fire. - Fuel level verified against the generator pickup height, not the dash gauge - Fuel pump output and filter condition checked at the inlet - Carburetor bowl, jets and solenoid inspected on gasoline sets - Diesel systems bled and lift pump pressure confirmed - Start circuit, solenoid and battery feed load tested ## Runs But Will Not Carry Load A set producing no output while running smoothly usually has a fault in the generator end rather than the engine. Brushes wear down and lose spring pressure against the slip rings. Slip rings themselves glaze or groove. Rotors lose residual magnetism after long storage and need to be re-excited. Capacitors on capacitor regulated sets fail open. Each of these produces the same complaint from the owner and each has a distinct test. Output that starts strong and then sags points elsewhere. Frequency dropping under load means the engine is not holding governed speed, which brings governor linkage, throttle response and fuel delivery back into the picture. Voltage falling while frequency holds means the excitation side cannot keep up. Separating those two readings during a load test is the fastest way to tell an engine problem from a generator problem on a set that technically runs. ## Routine Service, Exhaust and Mounting Scheduled service on an onboard set covers oil and filter, air filter, spark plugs on gasoline units, fuel filter, valve lash where the manufacturer specifies it, and inspection of belts and cooling passages. Air cooled sets accumulate debris in their cooling fins and shrouds, which raises operating temperature and shortens component life. Cleaning that out is unglamorous and makes a measurable difference on sets that live in dusty storage yards. Exhaust and mounting are safety items rather than performance items. Vibration isolators collapse over time, which transmits engine movement into the exhaust and cracks it. A cracked exhaust under a coach floor can put carbon monoxide into the living space. We inspect the full run, the tailpipe extension, the isolators and the mounting tray, and replace anything cracked, rusted through or no longer holding the set at the correct height and angle. - Oil, filters, plugs and fuel filter replaced to interval - Cooling fins and shroud cleared of accumulated debris - Vibration isolators inspected and replaced when collapsed - Full exhaust run checked for cracks and corrosion - Mounting tray and slide rails serviced on drawer mounted sets ## Load Banking and Proving the Repair Load banking is the difference between a generator that starts and a generator that works. A resistive bank applies load in measured steps while we watch line voltage, frequency, exhaust temperature and current on each leg. A healthy set holds voltage within a narrow band and frequency close to nominal from no load to full rating, and it does so after thirty minutes of running rather than only in the first two. The test also surfaces problems that never appear at idle. Cooling that is marginal shows as a climbing exhaust temperature. A partially blocked fuel filter shows as frequency droop only at the top of the range. A weak capacitor shows as voltage that will not recover after a step load is applied. Numbers from each step go on the paperwork so the owner has a baseline to compare against at the next service. ## Sequence of operations ### 01. Intake, history and no load run The set is started cold with no load while we record cranking behavior, time to fire, oil pressure, initial voltage and frequency. Service history and the amount the generator has actually been run get documented, because a set with twenty hours behaves nothing like a set with two thousand. ### 02. Branch diagnosis on engine or generator end Symptoms route the work down one of two paths. Starting and running faults go to fuel, ignition, compression and the start circuit. Output faults go to brushes, slip rings, rotor excitation, capacitor and control board. Testing follows the branch rather than replacing parts across both. ### 03. Repair, service and reassembly Authorized repairs are completed alongside any deferred routine service, since the set is already accessible. Carburetor or injector work, brush replacement, capacitor replacement, exhaust repair and isolator replacement happen in the same visit where the findings support them, which saves a second teardown later. ### 04. Load bank verification and documentation The repaired set runs against a resistive load in steps up to its rating for an extended period. Voltage, frequency, current per leg and exhaust temperature are recorded at each step and at temperature. Those figures go on the invoice as a baseline for the owner and for future service. ## Frequently asked questions ### My generator ran fine last season and now it will not start. What changed? Almost always the fuel. Gasoline left in a carburetor bowl through a warm storage season evaporates and leaves varnish that blocks the main jet and sticks the float. Diesel sets grow biological contamination and clog filters. Neither is a wear failure, and both are avoidable by exercising the set under load monthly and treating fuel that will sit. Cleaning and refreshing the fuel system usually resolves it. ### Why does my generator run but the air conditioners will not start? Starting a compressor demands several times its running current for a fraction of a second. A set with weak excitation, a failing capacitor, a fuel restriction or a governor that cannot recover from a step load will produce nominal voltage at idle and collapse the instant that inrush arrives. Load banking exposes exactly this. A soft start module on the roof air is sometimes part of the solution. ### Do you service diesel generator sets as well as gasoline? Yes. Diesel sets on diesel pusher coaches and commercial vehicles get fuel system service, filter and bleed work, injector evaluation, glow or preheat circuit testing, cooling system service, brush and excitation work and the same load bank verification. Liquid cooled sets add coolant condition, hose and thermostat inspection to the routine, since overheating is the most common cause of expensive damage on those units. ### Is generator work actually something this shop performs? It is a core service here. Onboard generator sets are treated as coach equipment, and this category covers them fully: service, fuel systems, ignition, excitation, control boards, exhaust, mounting and load verification. Vehicle engine and transmission work is a different matter and is not performed at this facility. If a diagnosis leads there, we document the finding and return the vehicle with it in writing. ### How often should an onboard generator be exercised? Once a month for roughly two hours with at least half the rated load applied. Running it unloaded does more harm than good on many sets, because it allows carbon to accumulate and never brings the unit to proper operating temperature. Two roof air conditioners or an electric water heater element make an adequate load on most coaches. This single habit prevents the majority of generator repairs. --- OCRV Center. 23281 La Palma Ave, Yorba Linda, CA 92887. (949) 799-3387. info@ocrvcenter.com. Serving Eastvale, California in Riverside County, about 20 miles from the shop. All work is performed in shop at the Yorba Linda facility. No mobile, roadside or on-site service is offered. Scope is body, paint, structural, fiberglass, interior and vehicle systems work. Engine rebuilds, transmission rebuilds, drivetrain work, DOT inspections and emission testing are not performed.