Onboard Systems
120 Volt Electrical Repair: Cost, Hours and Process in Hacienda Heights
120 volt electrical repair covers the AC side of a coach: the shore power inlet, the main breaker panel, GFCI protected circuits, receptacles and the hardwired loads on them. It is the side of the system where a fault is a fire and a shock risk rather than an inconvenience, so scope discipline matters more here than anywhere else.
What brings this in
- A GFCI that trips on plug in, or trips only when the water heater or a hair dryer runs
- Half the receptacles live and half dead, which usually means one leg of a 50 amp service is out
- A breaker that trips warm to the touch rather than instantly
- A burning or fishy odor near the panel, the inlet or a receptacle face
- Scorch marks or melted pins on the shore cord plug or the coach inlet
- Voltage reading well below 110 at a receptacle under load
- The reverse polarity indicator lit on the panel or a plug in tester
- Air conditioner and microwave that will not run together despite adequate service
This job, by the numbers
$285 to $5,000 plus
1 to 20 plus hours
In depth diagnostic, 1 hour at $285. One hour minimum. Credited to an authorized repair.
Parts and assemblies we work with
WFCO, Progressive Dynamics, Magnum, Xantrex, Furrion
Why a coach AC fault is different from a house AC fault
A house is a static structure with rigid conduit and terminations that never move. A coach is a vibrating platform with stranded wire, push in terminations and a cord that gets dragged across asphalt and stepped on. The failure modes that dominate are mechanical: a loosened backstab, a spread plug pin, a chafed conductor at a wall penetration.
Heat is the tell. A connection with high resistance generates heat, and heat discolors plastic before it starts a fire. When we open a panel or a receptacle box on an intake and find browned insulation or a heat mark on a bus bar, that is the fault, whether or not it is currently misbehaving.
The shore cord and the inlet are the two most abused components in the entire system. A 50 amp cord end that has been arcing at a pedestal for a season carries a spread pin, and the spread pin then damages every inlet it touches. That is why we look at both ends of the connection rather than replacing one.
GFCI trips, and what they are actually telling you
A GFCI is not a circuit breaker. It compares current out against current back and trips when a few milliamps are going somewhere else. It is doing its job when it trips, and the correct response is to find the leakage path, not to replace the device until one stops complaining.
In coaches, the leakage path is usually moisture. Exterior receptacles, the wet bay, the bathroom and the refrigerator compartment are the usual candidates. A water heater element with a hairline breach in the sheath will trip a GFCI on heat and pass every test cold, which is a maddening intermittent until it is measured hot.
The second cause is a shared neutral. Where a previous repair or an aftermarket addition tied a neutral to the wrong side of the device, the GFCI sees imbalance and trips even though nothing is faulty. Correcting that is wiring work, and it is common on coaches that have had an inverter or a residential refrigerator retrofitted.
- Moisture in an exterior, wet bay or bathroom receptacle
- A water heater element breached in the sheath, tripping only when energized
- A neutral tied downstream of the device by a previous repair
- A damaged extension or shore cord leaking to ground through a cut jacket
- An aged GFCI at end of service, which does happen but is not the first suspect
Cost, hours and the safety line we hold
Diagnosis on this page is the in depth diagnostic tier: one hour at $285, credited against an authorized repair. Repair labor runs at the posted mechanical and electrical rate of $260 per hour. A receptacle, a breaker or a GFCI is often inside two hours. An inlet, a panel replacement or a rewire of a damaged run climbs to the upper end of the band.
There is one thing we will not do, and it is worth stating. We do not close up a coach with a known AC fault deferred because the owner would rather wait. A 12 volt fault left alone is an inconvenience. A 120 volt fault left alone is a fire in a wood and foam structure with one exit. If the scope has to be phased for budget, the safety items go first and the cosmetic repair waits.
Insurance rarely applies to a 120 volt repair itself, because the cause is normally wear or a prior installation. Where an AC fault caused consequential damage such as a burned compartment or smoke through the interior, that damage is a claim and we document it that way.
Scope
What this line item does not include
- We do not perform electrical work at a pedestal, a campsite or a storage yard. AC faults are bay work.
- Park pedestal and campground wiring faults are the park operator's responsibility, not a coach repair.
- Adding an inverter or a subpanel is an upgrade line item rather than a repair.
Being explicit about the boundary is faster than discovering it at pickup. If the work you need sits outside this line item we will say so at intake and point you at the right one.
Questions
120 Volt Electrical Repair questions
Why does my RV GFCI trip as soon as I plug in?
Something on that circuit is leaking current to ground, and the device is doing exactly what it exists to do. In coaches the leakage is usually moisture in an exterior, wet bay or bathroom receptacle, or a water heater element breached in the sheath. Replacing the GFCI without finding the path just moves the problem and removes your protection while you wait for it.
Half my outlets work and half do not. What is that?
On a 50 amp coach that is almost always one lost leg. A 50 amp service is two 120 volt legs, and half the panel hangs on each. Lose one at the pedestal, at the cord end, at the inlet or at the main, and half the coach goes dark while the other half works normally. We read both legs at the inlet first, because that separates a coach fault from a park fault in about five minutes.
Can you replace the whole breaker panel in a coach?
Yes, and it is the right call when the bus bar shows heat damage or the panel is a discontinued unit with no available breakers. Most coaches carry a WFCO or Progressive Dynamics combination panel that includes the converter, so a panel job usually addresses the DC distribution and the converter at the same time. Lead time on the assembly is 3 to 10 business days.
My shore cord plug is melted. Do I need a new inlet as well?
Usually yes, and this is the part owners are surprised by. A melted or spread plug pin means the connection was running hot, and heat damages both halves. Fitting a new cord end into a damaged inlet reproduces the fault in a few weeks. We inspect and read both sides, and where only one is compromised we say so rather than selling the pair.
Related work
Often done at the same time
$285 to $1,500
Transfer Switch and Shore Power Repair
Inlet, cord, automatic transfer switch and surge protection repair on the 120 volt supply path.
$400 to $5,500
Wiring and Fuse Panel Repair
Harness repair, panel replacement and correction of prior wiring work, including rodent and chafe damage.
$750 to $4,500
Inverter and Converter Repair
Diagnosis and replacement of coach converters, inverters and combined inverter chargers, including transfer and cutoff settings.
$285 to $5,000 plus
12 Volt Electrical Repair
DC side diagnosis and repair: battery bank, distribution panel, grounds and the branch circuits off them.
Get a firm number on 120 volt electrical repair
The band on this page is honest, and the in depth diagnostic at 1 hour at $285 turns it into a firm number. One hour minimum. Credited to an authorized repair. We are 18.4 miles from Hacienda Heights.