RVs and Motorhomes
Custom Converted RVs Repair
The short answer
A custom converted RV is any vehicle turned into living space outside a factory line, from ambulance and box truck conversions to owner-built coaches. With no factory drawings and unknown structure behind the panels, assessment comes before any repair. We diagnose, correct, and rebuild these in Yorba Linda.
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What we see on custom converted rvs
The defining feature of a custom conversion is the absence of information. There are no factory drawings, no service manual, no wiring diagram, and no way to know what is behind a wall until it is opened. Two conversions that look identical from outside can be built completely differently, one with properly framed and bonded openings and load-spread mounting, the other with cabinets lag-bolted into sheet metal and a fan opening cut through a structural rib. That means our first task on nearly every custom unit is investigation rather than repair, and we bill that as diagnostic time at $285 per hour, refundable against an authorized repair.
The failures cluster in predictable places regardless of the base vehicle. Openings cut without reinforcement crack at the corners. Fasteners driven into unsupported panel work loose and let water in. Electrical work done by a builder without a rated understanding of DC loads produces undersized wire, missing overcurrent protection, and connections that heat under load. Propane runs installed without proper support chafe against structure. None of that is exotic, and all of it is the reason a conversion that has been on the road two years arrives with what the owner describes as several unrelated problems.
Southern California use adds its own pattern. Conversions built for desert and mountain travel see 115 degree heat soak in Indio and Palm Desert followed by freeze cycling at Big Bear Lake within the same month, and construction adhesives and sealants chosen for convenience rather than for temperature range fail early under that swing. Insulation installed without a vapor strategy then condenses moisture inside the wall during the cold end of that cycle. We open a lot of custom walls and find dry-looking panel over wet insulation.
Location: All work is performed at our Yorba Linda facility. We do not offer mobile, roadside, or fleet route service.
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What makes this vehicle different
- Base vehicle can be a box truck, ambulance, van, shuttle, or stripped chassis
- No factory documentation, drawings, or wiring diagrams for the conversion work
- Highly variable build quality, with structure hidden entirely behind finished panel
- Mixed materials in one assembly, frequently wood, steel, aluminum, and composite together
- Owner or small-shop electrical systems with non-standard wire routing and protection
- Openings cut into structural panels with varying levels of reinforcement
- Insurance valuation that depends on documented build cost rather than a book value
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What actually fails, and why
Cracking at unreinforced cutouts
Windows, fans, and doors cut through structural panel without a bonded reinforcing frame create stress risers at each corner. Cracks propagate diagonally with road input and keep growing until the opening is properly reframed rather than filled.
Electrical faults from undersized or unprotected wiring
Conversion twelve volt systems commonly run wire sized for the appliance rather than the run length, with fusing missing or wrong. Symptoms present as voltage drop, connections that heat under load, and inverters that fault at partial output.
Water entry at roof penetrations without proper flanges
Fans and vents bedded in sealant alone rather than mounted to a flanged and reinforced opening always leak eventually. Because the interior is finished, water travels inside the wall and reaches the floor before anything appears on a ceiling.
Loose or failing cabinetry and equipment mounts
Heavy cabinetry, batteries, and tanks fastened into unsupported sheet metal work their fasteners loose. On grade descents like the 74 and the 38 those loads shift dynamically and elongate the mounting holes further each trip.
Hidden condensation and insulation saturation
Insulation installed without a vapor strategy condenses moisture against cold panel during the swing between low desert heat and mountain cold. The visible surface stays dry while the insulation behind it stays wet and corrodes the panel from inside.
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Services we perform on custom converted rvs
Service
12V and 120V Electrical Diagnostics and Repair
Electrical diagnostics traces 12V DC and 120V AC faults on RVs, vans, trailers, and fleet units, including dead circuits, parasiti
Service
Custom Van Build-Out and Camper Conversion
A custom van build-out converts an empty cargo van into a camper, mobile workshop, or purpose-built work vehicle with insulation,
Service
Structural Welding and Fabrication
Certified in-shop welding and fabrication on steel and aluminum structure. Covers frame repair, custom bumpers and racks, reinforc
Service
Insulation and Sound Deadening
Insulation and sound deadening work adds thermal and acoustic control to walls, ceiling, floor, and wheel wells using constrained
Service
Water Damage and Subfloor Replacement
Water damage restoration covers soft floors, rotted subfloor, failed wall substrate, and the seal failure that caused it. Work run
Service
Roof Vent and Fan Replacement
Roof vent and fan replacement covers cracked lids, failed hinges, dead motors, and full powered fan upgrades in the standard 14 by
Service
Cabinetry Repair, Refacing and Custom Build
Cabinetry work covers delaminated doors, blown-out hinge screws, sagging shelves, refacing, and full custom box fabrication in the
Service
LP Gas System Service and Leak Repair
LP gas service covers pressure and leak testing, regulator replacement, line and fitting repair, tank valve service, and appliance
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On the insurance side
Conversions are valued from documentation, not a book. We photograph and itemize every modification during disassembly so installed equipment appears in the supplement.
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Questions about custom converted rvs
Frequently asked questions
How do you estimate a repair when nobody knows how it was built?
We investigate first. That means removing panels selectively, tracing wiring, and inspecting structure at the points most likely to be compromised, billed as diagnostic time at $285 per hour, refundable as a credit against an authorized repair. Trying to write a fixed estimate on a conversion without opening it produces a number that is wrong in both directions.
Will my insurance cover a custom conversion?
Coverage and valuation depend on documentation. Carriers pay against demonstrable value, so build receipts, photographs of the build in progress, and an itemized list of installed equipment matter enormously. During any repair we photograph and itemize modifications specifically so they end up in the supplement rather than being treated as unlisted equipment.
Can you fix electrical work someone else did?
Yes, and we usually start by mapping what is actually installed rather than trusting the previous diagram. We check wire gauge against run length and load, verify overcurrent protection at every source, inspect terminations for heat damage, and correct routing where wire passes through structure unprotected. Electrical labor is billed at $260 per hour.
My conversion smells musty but I cannot find a leak. Where do I look?
In our experience that is usually insulation holding moisture rather than an active leak. Condensation forms against cold metal panel where there is no vapor control, and the interior surface stays dry the whole time. We take moisture readings, then open a small section at the lowest point of the wall, which is where saturated insulation shows first.
Do you take on partially finished builds?
Yes. We assess what exists, tell you plainly what has to be redone versus what can be built on, and finish the structure, insulation, cabinetry, flooring, and systems. Being honest about the redo list up front is the whole point. Building finished surfaces over structure that will fail is the most expensive thing an owner can pay for twice.
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More rvs and motorhomes
Bring your custom converted rvs to the shop in Yorba Linda.