RV OWNER’S FIELD GUIDE
Electrical & Shore Power Troubleshooting
Shore power problems and flickering lights are the most common calls we get. This page covers the wiring/power-supply side of things — for battery charging and capacity issues, see our dedicated Battery & Charging Systems Guide.
SYSTEM VOLTAGE NOTE
This guide covers a standard 12V DC house battery system — the overwhelming majority of RVs. If your rig runs a 24V or 48V inverter/charger system (common with larger Victron MultiPlus/Quattro or Xantrex installs), see our Victron Fault Code & Diagnostics Guide — resting and charge-stage voltages scale proportionally and don’t translate directly from the 12V figures below.
Shore Power Not Working at Your Campsite?
Start at the source before assuming your rig is the problem. Work through this in order:
1. Check the campground pedestal breaker first — it may have tripped
2. Inspect your shore power cord for burnt or melted pins at both ends
3. Check your coach breaker panel — reset tripped breakers, but if one trips again there’s an underlying cause
4. Test your 30/50 amp adapter — adapters corrode and fail more often than people expect
5. Verify pedestal voltage (120V AC) — anything under 108V AC can damage appliances silently over time
PRO TIP
A surge protector with voltage monitoring is one of the best investments an RV owner can make. It protects your AC, microwave, and converter from low-voltage damage and pays for itself after one bad pedestal.
Battery Draining Overnight?
A battery that reads full at bedtime and dead by morning almost always means a parasitic draw — a detector, control module, or radio left wired hot, an aging battery near end of life, or a converter/inverter drawing current in standby. Finding the actual draw means pulling fuses one at a time while watching current draw on a meter, not guessing.
For full battery chemistry, charging, capacity-testing, and maintenance guidance, see our dedicated Battery & Charging Systems Guide.
Flickering Lights or Dimming Under Load
Lights that dim when the water pump or furnace fan kicks on point to voltage drop somewhere in the circuit — usually a loose or corroded connection, not the light fixture itself.
— Check battery terminal connections for corrosion or looseness first — the most common cause
— Inspect ground connections at the chassis and distribution panel
— A weak or sulfated battery can’t supply current under load even if it reads normal voltage at rest
— Undersized wire on an aftermarket accessory circuit can pull down the whole 12V bus under load
A proper diagnosis measures voltage drop across each connection point under actual load with a DVOM — that’s the only way to isolate exactly where the resistance is.
Converter Not Charging Properly
A converter that undercharges leaves your battery chronically low; one that overcharges cooks it early. Neither failure mode is obvious without testing. Internal converter fuses are a common failure point and are often overlooked. Multi-stage converters that never leave bulk charge mode indicate a charge-stage sensing fault.
For brand-specific fault codes and charge-stage behavior, see our Victron Fault Code Guide or PD/WFCO/Xantrex Fault Code Guide.
When to Stop and Call a Professional
If you’ve worked through the steps above and still have nothing, or if you smell burning, see scorch marks at any connection, or a breaker trips instantly every time it’s reset — stop troubleshooting and get it looked at properly. Electrical faults that aren’t diagnosed correctly get more expensive the longer they run, and some are genuine fire risks. Thermal imaging and a quality DVOM find in minutes what visual inspection misses entirely.