No power / dead coach

Start safe. Confirm the pedestal breaker and your shore cord ends before opening panels. Do not stand in wet ground while resetting a GFI pedestal, and do not bypass a failed EMS by jerry-rigging bare copper. Unplug before you poke inlet blades. A dark coach is often an open breaker, a failed surge protector/EMS, a converter that quit, a GFCI that tripped, or a battery disconnect that got bumped — not “the inverter is dead forever.”

Symptoms

• Whole coach dark on shore — no 120V outlets, converter quiet, EMS dark or faulted
• House 12V dead (lights, slides, furnace board, water pump) while microwave/AC still work on shore
• Both 120V and 12V dark after overnight storage or a pedestal change
• Intermittent brownouts when AC + microwave load up; lights flicker, EMS chatters
• Inverter beeping / no pass-through while shore cord is seated
• GFCI outlets dead in kitchen/bath after rain or a wet bay

Quick path (owner-safe)

1. Verify pedestal power; try a known-good outlet or different pedestal when possible. Confirm the shore cord is fully seated at both ends and the dogbone (if any) is rated for your amp service.
2. Check coach main breakers and the EMS / surge protector status lights. Note any fault LEDs or open-ground / reverse-polarity / low-voltage rejects before you reset anything twice.
3. Reset GFCI receptacles and any mid-bay GFCI / ELCI protectors once — if they trip again under no load, stop and Prefer Text.
4. Listen/feel for the converter fan; measure converter output and battery voltage with a DVOM if you have one. Write the numbers down at the battery posts, not only the panel meter.
5. Separate 120V symptoms from 12V drain (lights, slides, furnace board, water pump). If 12V is alive and 120V is not, stay on the shore / breaker / EMS path.
6. Check the battery disconnect switch and any main house fuse / ANL / MIDI fuse before you condemn the bank. A bumped disconnect looks exactly like a “dead coach” at night.

Symptom forks

• No 120V only — shore / EMS / breaker / GFCI path; house 12V may still be fine. Do not start by replacing the inverter.
• No 12V only — battery, disconnect, converter/charger, or a main fuse. Lights and slides go dark while the microwave might still work on shore. See also house battery not charging.
• Both dark — start at the pedestal and work inward. Confirm the coach is not on storage mode or a parasitic drain that killed the bank overnight.
• Intermittent / brownout — loose shore pin, weak pedestal, undersized dogbone, or converter thermal foldback under AC + microwave load. Note when it fails.
• Inverter alarms / no pass-through — overload, low-battery cutout, or transfer fault. Work that tree on inverter / shore-power faults instead of swapping the MultiPlus first.
• One leg only on 50A — pedestal or transfer issue on one hot; don’t assume “half the coach needs a new inverter.”

Owner checklist (photos help)

• Pedestal breaker amp rating vs your cord (30A vs 50A adapters matter).
• EMS / surge protector model and any fault code on the display.
• Converter / charger brand and model sticker; Victron users — note MultiPlus / Cerbo / VictronConnect fault text.
• Battery type (flooded / AGM / Li) and resting voltage if you can measure it at the posts.
• Year / make / model of the coach and where you are parked (city or ZIP for a trip quote).

Deeper notes: converter, inverter, breakers, GFCI

Converters and inverter-chargers are not the same job. A simple converter may only charge; a Victron MultiPlus / Quattro (or similar) also inverts and passes shore through a transfer path. If shore is good and the EMS is green but the converter never wakes, measure DC at the bank under shore — zero climb points at charge path or a blown DC fuse. GFCI trips that return under no load are wiring or moisture issues. Breakers that won’t reset or feel hot need a stop — Prefer Text rather than forcing the handle.

Lithium BMS lockout can look like a totally dead 12V house. Confirm disconnect and main fuse first, then BMS state in the app. Charge-only mysteries: 12V battery no-charge. Transfer and overload codes: inverter / shore-power faults.

When to stop DIY

• Burning smell, scorched shore plug, or melted adapter — unplug and Prefer Text.
• You need to open sealed EMS housings or cut factory harnesses to “test.”
• Lithium BMS lockout you cannot clear with the OEM recovery steps, inverter AC-out faults that return instantly, or neutral-ground bonding questions on a bonded pedestal.
• Any work that requires thermal imaging of hot breakers or torque on lug connections you are not equipped for.
• Water intrusion in the inverter bay or converter compartment — treat as electrical + moisture, not a parts swap.

What UMRT diagnoses

United Mobile RV runs diagnostics-first metering (DVOM / thermal where needed) as a Victron Professional Certified Installer. We quote the trip before we roll, then apply the diagnostic toward repair if you proceed. Typical on-site work: pedestal-to-inlet integrity, EMS interpretation, breaker / GFCI mapping, converter vs inverter-charger charge path, cable drop and ground quality, and separating “dead bank” from “dead charge source.”

Trip $75 / 30 mi then $1.50/mi · labor ~$150/hr (1 hr min / 30-min increments) · diagnostic $175 applied if you proceed. Active corridor: MT · WY · ID · WA (case-by-case beyond).

Related guides & siblings

Deep dive: Electrical troubleshooting · Solar & battery · Victron fault codes. Siblings: 12V battery no-charge · Inverter / shore-power faults · Generator won’t start. Hub: Troubleshoot.

Prefer Text — (616) 606-5277. Trip $75/30 mi then $1.50/mi · labor ~$150/hr (1 hr min / 30-min) · diagnostic $175 applied. Winterize $175 · trip-prep $225. Credentials: Victron Professional Certified Installer · weBoost Authorized Installer · Peplink Certified Associate · Dometic Professional Certified.