Electrical and Power
Electrical System Repair
In short: Most RV electrical faults are connection faults rather than component faults, which is why replacing a converter or an inverter usually fails to fix the problem the second time as reliably as it failed the first.
- Typical range
- $500 to $8,500+
- Labor hours
- 2 to 35 hours
- Updated
Electrical faults in recreational vehicles and fleet vehicles get misdiagnosed more than any other category, and the reason is consistent: the symptom appears at a component, so the component gets replaced, but the fault is in a connection somewhere upstream.
A converter that will not charge, an inverter that shuts down under load, lights that dim, an appliance that works on shore power and not on battery. All of those present as component failures and most of them are connections.
Two systems, one vehicle
The 12 volt DC system runs from the house battery bank through a distribution panel to lighting, water pump, fans, slide and awning motors, control boards on appliances, and the ignition and charging systems on a motorised chassis. It is low voltage and high current, which means resistance matters enormously: a connection that would be trivial at 120 volts causes visible voltage drop at 12.
The 120 volt AC system runs from shore power or a generator, through a transfer switch, into a breaker panel and out to outlets, air conditioning, microwave, water heater element and the converter that charges the batteries. It behaves like household wiring with two differences: it is in a vehicle that vibrates, and it can be fed from three different sources.
Most vehicles also have an inverter bridging the two, which is where solar, inverter and battery work comes in.
What actually fails
Connections. Corroded grounds, loose terminals, poor crimps, and wire nuts used where a crimp belongs. This is the largest category by a wide margin. Vibration works every joint continuously and any joint that was marginal on day one will eventually be open.
Grounds specifically. More faults trace to a bad ground than to a bad positive, and grounds are harder to find because everything downstream of a poor ground behaves oddly rather than failing outright.
Batteries. A bank at end of life presents as everything else being wrong.
Converters and chargers. Genuinely fail, but frequently as a consequence rather than a cause.
Transfer switches. The component that decides between shore and generator power. They arc, they weld contacts, and they fail in ways that read as a generator fault.
Rodent damage. Common in stored vehicles. Chewed insulation in multiple locations.
Water intrusion. Corroded terminations in a cavity that has been wet. This is a fire risk and it is the reason electrical inspection is part of any water damage job.
Aftermarket work. Undersized cable, unfused branches, connections made in inaccessible places by a previous owner or a fast shop.
How we diagnose
Diagnosis before parts, every time.
Voltage drop testing under load across each connection in the suspect circuit. This is the test that finds a bad joint, and it is the test most commonly skipped in favour of replacing the component at the end of the wire.
Load testing on the battery bank, because a bank that measures fine at rest can collapse under load. Thermal inspection to find connections running hot, which is the signature of resistance. Continuity and insulation testing on suspect runs. And on the AC side, verification of the incoming supply, because out-of-specification shore power damages equipment and is not the vehicle's fault.
Diagnostic labor is $285 per hour with a one hour minimum, credited back against an authorized repair.
What we do
Circuit and connection repair, rewiring of affected runs, distribution panel and breaker panel repair or replacement, converter and charger replacement, transfer switch replacement, shore power inlet and cord repair, 30 to 50 amp service upgrades, generator connection and control wiring, chassis and engine electrical on motorised units, lighting upgrades and LED conversions, and full rewires on restoration and conversion projects.
On commercial and fleet vehicles this extends to emergency lighting, siren and control wiring, lift gate power, auxiliary battery systems and telematics installations.
What it costs
| Job | Typical range | Hours |
|---|---|---|
| Diagnosis | $285 first hour | 1 to 3 |
| Connection or circuit fault repair | $500 to $1,500 | 2 to 6 |
| Converter or charger replacement | $900 to $2,200 | 3 to 8 |
| Transfer switch replacement | $900 to $2,000 | 3 to 7 |
| Distribution panel replacement | $1,500 to $3,000 | 6 to 12 |
| Service upgrade to 50 amp | $2,000 to $4,500 | 8 to 18 |
| Rodent damage, multiple runs | $1,500 to $5,000 | 6 to 20 |
| Full rewire | $4,500 to $8,500 | 20 to 35 |
Electrical labor is $260 per hour. See the pricing page.
Safety, plainly
An electrical fault in a vehicle that people sleep in is a different risk from an electrical fault in a house. There is less structure between the fault and the occupants, the vehicle vibrates continuously, and there is frequently propane in the same space.
We do not patch electrical faults. A chafed run gets replaced rather than taped, an undersized cable gets resized rather than fused down, and an unfused branch gets a fuse. If that makes an estimate larger than expected, that is the reason.
Estimates are $150 and credited back against an authorized repair.