# RV Mechanical and Systems Repair Services > Mechanical and systems services cover the four things that make a coach livable: electrical, generator, plumbing and appliances. Four service lines sit here. Mechanical and electrical labor is posted at $260 per hour, diagnostics at $285 per hour with a one hour minimum applied as a credit against an authorized repair. Source: https://ocrv.biz/services/mechanical-systems/ Business: OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887. (949) 799-3387. Serving Tustin, California. Ballpark range: $285 to $5,000. Posted rates at https://ocrv.biz/prices/ ## Why does systems work start with a paid diagnostic? Because the fault has to be reproduced before anyone can quote it honestly, and reproducing an intermittent fault takes time on the clock. An RV systems estimate is $150, applied as a credit against an authorized repair. An in depth diagnostic is 1 hour at $285, also applied as a credit. Both cover slide, awning, water, electrical and generator evaluation. The reason is structural to how these vehicles are built. A coach carries two independent electrical systems, a propane system, a fresh water system, two waste systems, a generator, an inverter, a converter, a transfer switch and up to a dozen appliances, all installed by different suppliers into wiring runs buried inside walls. A symptom of "the outlets do not work" can be a tripped GFCI in the wet bay, a failed transfer switch, an inverter in fault, a breaker in the distribution panel, a shore cord with a burned neutral or a converter that stopped charging. Each of those is a different part and a different labor line. Guessing costs the owner more than diagnosing. A shop that quotes over the phone is quoting the most likely cause, and when it turns out to be the second most likely cause the owner pays for both. The credit structure exists so the diagnostic time is not lost money once the repair is authorized. Electrical diagnostics and repair spans $285 to $5,000 across 1 to 20 hours, which reflects the range from a bad ground to a rewired distribution panel. Full bands sit on the [price sheet](/prices/). ## What are the four service lines under this category? - [Electrical Repair](/services/electrical-repair/): 12-volt and 120-volt systems, batteries and charging, solar, inverters and converters, wiring and fuse box work. This is where the LiFePO4 conversions and shore power faults land. - [Generator Repair](/services/generator-repair/): Onan and Cummins service, load testing, overhaul and new generator installation. Service runs $400 to $8,500 across 2 to 35 hours. - [Plumbing Repair](/services/plumbing-repair/): fresh water, black and gray tanks, water heaters, toilets, sinks and showers, pumps and valves. - [Appliance Repair](/services/appliance-repair/): refrigerators, cooktops and ovens, microwaves, air conditioners, furnaces and heating systems including AquaHot hydronic. Note what is not here. Engine, drivetrain and chassis powertrain work is not performed at this facility. The shop does body, paint, structural, systems and equipment installation. If the chassis engine needs attention, that goes to a chassis dealer, and the coach comes here for everything above the frame rails. ## AGM or LiFePO4: what changes in the rest of the system? More than the batteries. Swapping a lead acid house bank for lithium iron phosphate changes the charging profile, the current the system can deliver, the temperature limits and the wiring requirements. Doing it as a drop-in replacement without addressing those is the most common way owners burn up a converter. AGM is an absorbed glass mat lead acid battery. It charges on a three stage profile of bulk, absorption and float, tolerates being float-charged indefinitely, and delivers usable capacity down to about 50 percent depth of discharge before life shortens sharply. It is heavy, roughly 60 pounds per 100 amp hours, and it is forgiving. LiFePO4 charges on a two stage profile with no float stage, holds nearly full voltage across the discharge curve, delivers usable capacity to 80 or 90 percent depth of discharge, and weighs roughly a third of the equivalent AGM. It also refuses to accept charge below freezing without an internal heater, and it can accept charge current so fast that an undersized cable or an unprotected alternator becomes the limiting failure point. A correct conversion means verifying the converter or charger can output a lithium profile, verifying the inverter low-voltage cutoff is set for the new chemistry, sizing cable and fusing for the new current capability, adding a DC to DC charger if the bank charges off the chassis alternator, and confirming the battery monitor is shunt based rather than voltage based, because voltage tells you almost nothing about a lithium state of charge. House battery replacement runs $500 to $5,500 across 2 to 10 hours; solar installation runs $1,500 to $12,000 across 8 to 40 hours. ## What does Onan generator service actually involve? Generators fail from disuse far more often than from wear. The standing recommendation from Onan is to exercise the unit under load for a couple of hours monthly, and the units that arrive here with problems are almost always the ones that sat. Gasoline units suffer first. Fuel varnishes in the carburetor bowl and the jets, so the unit cranks and will not start, or starts and drops off under load. Carburetor service, and often replacement, is the fix. Diesel units suffer differently: injector and fuel system issues, and air in the fuel line after sitting. Scheduled service is oil and filter, air filter, spark plugs on gasoline units, fuel filter, and a slip ring and brush inspection on the generator end. The critical step most owners skip is the load test. A generator that starts and runs at no load can still fail to carry two air conditioners, and the only way to find that before a hot afternoon in the desert is to put a load bank on it in the shop. Generator work runs $400 to $8,500 across 2 to 35 hours, covering everything from a scheduled service through a full overhaul and reinstallation. Generator slide trays, exhaust systems and the wiring between the generator and the transfer switch are all part of the same scope. ## How do fresh water and waste faults get traced? By pressure and by section. A fresh water system holds pressure; a leak is found by pressurizing the system with the pump off and watching the gauge, then isolating sections until the drop stops. Running the pump and looking for wet spots finds only the leaks that are already visible. PEX has largely replaced the old grey polybutylene, and it fails at crimp fittings rather than in the middle of a run. A crimp that was made slightly off-square will hold for years and then weep, which is why a full fresh water job includes checking every accessible crimp rather than only the one that is dripping. Waste systems fail differently. Tank sensors read wrong because residue coats the probes, not because the sensors are broken, so replacing them without cleaning the tank produces the same wrong reading a month later. Gate valves fail from debris on the seat and from being left open. Tank cracks come from freezing, from road impact and from mounting straps that loosened and let the tank flex on its own weight. Fresh water service runs $285 to $4,500 across 1 to 18 hours. Black and gray tank repair and replacement runs $750 to $8,500 across 5 to 35 hours, and the labor spread reflects how much has to come apart to reach a tank on a given floorplan. Water heater service, including Truma and AquaHot units, runs $350 to $4,500. ## How this job runs 1. **Reproduce the fault**: The symptom is recreated in shop under the conditions the owner reported, on shore power, on generator, on battery, or with the system loaded, so the diagnosis is based on observed behavior rather than description. 2. **Isolate the circuit or section**: Electrical faults are traced by section with a meter under load, not by continuity alone. Water faults are isolated by pressure test section by section. Propane faults are isolated by manometer drop test. 3. **Quote the repair against the diagnosis**: The written estimate names the failed component, the labor operation and the parts. The diagnostic charge is applied as a credit once the repair is authorized, so the evaluation time is not paid for twice. 4. **Repair and verify under load**: The system is tested in the same condition that produced the fault. Generators go on a load bank, water systems are pressure held, and electrical repairs are verified with the circuit carrying its rated draw. ## Questions ### My converter is not charging the batteries. Is the converter bad? Sometimes. It is just as often a tripped breaker on the input side, a failed transfer switch, a corroded battery ground or a battery so deeply discharged the converter reads it as absent. That is why the diagnostic is charged as time and applied as a credit rather than quoted as a part swap. ### Do you install solar and lithium together? Frequently, because they complement each other. Solar installation runs $1,500 to $12,000 across 8 to 40 hours, and combining it with the battery conversion means the charge controller, the inverter settings and the monitoring shunt all get configured once for the finished system. ### How often should the generator be serviced? Follow the hour interval in the unit manual, and exercise it monthly under load between services. Generators that sit unused for months are the ones that arrive here with varnished carburetors and no-start conditions, and that repair costs more than the service would have. ### Can you service an AquaHot system? Yes. Hydronic heat service, including AquaHot, runs $750 to $8,500 across 3 to 35 hours. These systems heat a glycol loop with a diesel burner and an electric element, then distribute heat to zone exchangers and to domestic hot water, so a fault can be in the burner, the pump, a zone valve or the control board. ### Do you work on the chassis engine? No. Engine, drivetrain and related chassis powertrain work is not performed here. This shop covers body, paint, structural, house systems and equipment installation, which is where the specialized tooling and the technicians are. ## Related - [Services](https://ocrv.biz/services/) - [Electrical Repair](https://ocrv.biz/services/electrical-repair/) - [Generator Repair](https://ocrv.biz/services/generator-repair/) - [Plumbing Repair](https://ocrv.biz/services/plumbing-repair/) - [Appliance Repair](https://ocrv.biz/services/appliance-repair/) - [Inspection and Evaluation](https://ocrv.biz/services/inspection-evaluation/) - [Prices and Posted Rates](https://ocrv.biz/prices/)