Camper Van Conversion Repair for Upfitter Builds

Nobody Documented This Build

On a factory built coach we can look up where the wiring runs, which openings the builder cut and what the furniture part numbers are. On a conversion, none of that exists. The person who built it knew, and they are usually not available, and even a professional upfitter rarely provides an as built drawing with the van.

That means the first thing we do is survey. We map what we can see, trace circuits, locate penetrations, identify tank and battery locations, and photograph everything before a single fastener comes out. That survey is real labor and it is in the estimate honestly rather than hidden in a supplement later.

Owners sometimes push back on paying for a survey. The alternative is a shop that opens a wall, cuts a circuit nobody knew was there, and hands you a bill for finding out. The survey is the cheaper version of the same information.

• Trace and label circuits before disassembly
• Locate tanks, pumps and battery banks and their runs
• Map every roof and wall penetration and its sealing method
• Photograph the build in detail before anything is removed
• Identify what is fastened to structure and what is fastened to skin

Every Penetration Sealed by a Different Hand

A conversion typically has a roof fan, sometimes two, often solar mounts, a refrigerator or heater vent, a shore power inlet, a water fill, and cable glands. Each was cut and sealed by whoever was doing that stage of the build, to whatever standard they held that day, and there is no consistency between them.

So water intrusion on a conversion is rarely one leak. We commonly find two or three entries in a single van, which is why chasing the stain fails here more than on any other vehicle. A water test working systematically from the bottom up is the only reliable method, and it takes real time on a van with eight penetrations.

Doing it right means going back to bare substrate at each penetration, checking the steel for corrosion around the cut edge, and re bedding with the correct material for that joint. Butyl, urethane and lap sealant are not interchangeable, and a large share of what we redo was sealed with whatever was in the garage.

Aftermarket Electrical With No Diagram

House electrical is where conversions get genuinely dangerous. We regularly find lithium banks with undersized cable, no fusing at the battery, fusing sized to the wire rather than the load, chassis grounds through a cabinet screw, and inverter output tied into the same run as twelve volt lighting.

None of that is a criticism of ambitious owners. It is the predictable result of building a complex system from forum advice without a diagram. What it means for repair is that we will not simply reconnect what was there after a body repair, because putting known bad wiring back is not something a shop should do.

The usual path is to correct what we disturb to a defensible standard, document what we found in the rest of the system, and give you a scoped quote to fix the rest. You choose whether to do it. What you get either way is a written record of what is in your van, which most conversion owners have never had.

• Fusing at the battery, sized to the conductor
• Cable sized for the actual load and run length
• Grounds landed on structure, not on cabinet hardware
• Inverter output kept separate from low voltage runs
• A written diagram of the system as it actually exists

Cabinetry Fastened to Sheet Metal

The other common build shortcut is fastening cabinetry, beds and appliance mounts into the van's thin sheet metal rather than into structure. It holds fine sitting still. Under braking, over a rough road, or in a collision, those fasteners tear through the skin and the cabinet becomes a projectile.

When we rebuild an interior after damage, we land structural fasteners on ribs, pillars and floor structure, with backing plate where the load justifies it. That is not gold plating, it is the difference between an interior that stays put and one that redistributes itself during a hard stop.

It also affects body repair. A cabinet screwed into a side panel means the panel cannot be worked from the back without removing the cabinet, and the fastener holes themselves are corrosion sites we have to address while we are in there.

Insulation, Condensation and the Rust Underneath

This is the failure conversion owners least expect. Insulation installed tight against bare steel, with no vapor management and no gap, traps condensation against the metal. The van looks perfect from inside and outside while the sheet metal behind the panel corrodes for years.

We find it when a body repair opens a wall, or when an owner notices a stain low on a panel that has no leak above it. By that point there can be perforation. The repair is cutting out the corroded metal, replacing it, treating the area properly, and reinstalling insulation with an approach that does not trap moisture again.

A worked example: a rear quarter repair on a conversion with cabinetry removal, no corrosion found, typically 18 to 28 hours of body and paint at $210 for $3,780 to $5,880, plus 6 to 10 hours of interior removal and reinstallation, plus $700 to $2,000 in materials. Add corrosion repair and the number climbs quickly.