Step-by-step diagnostic guides to help you identify, troubleshoot, and repair the most common RV problems.
DecisionGrid is structured as a diagnostic system, not a blog. Each hub links to specific problems, diagnostic flows, and repair guides. Start where your symptoms match.
AC not cooling, blowing warm air, freezing up, thermostat, capacitor failure. Rooftop AC electrical and mechanical diagnosis.
Breaker tripping, outlets dead, inverter not working, shore power not working, battery not charging. Shore power and 12V systems.
Water pump not working, water heater not working, plumbing leaks, toilet not flushing. Fresh water, hot water, and waste systems.
Battery draining, solar not charging, generator not starting, converter problems. 12V, charging, and generator systems.
Roof leaks, slide-out problems, leveling system, winterizing. Seasonal and structural maintenance.
Most common RV AC symptoms and where to go for diagnosis. Follow the symptom that matches your setup.
Step-by-step flowchart — pick your symptom
AC not cooling, not turning on, freezing up, short cycling, warm air
Start here →Runs but air is warm
Filter, refrigerant, capacitor, low voltage, frozen evaporator
Full diagnostic guide →Fan runs, warm air from vents
Filter, refrigerant, capacitor, compressor
Full diagnostic guide →No power, no display
Power, thermostat, 12V supply, breaker
Full diagnostic guide →Fan runs, compressor won't start
Capacitor, voltage, control board
Full diagnostic guide →Display blank, wrong mode, wiring
Batteries, mode (Cool vs Heat), loose wires
Full diagnostic guide →Ice on evaporator
Restricted airflow, dirty filter, low refrigerant
Full diagnostic guide →Runs briefly, stops, repeats
Thermostat, freeze sensor, capacitor, overload
Full diagnostic guide →Fan spins, compressor not cooling
Capacitor, compressor, refrigerant
Full diagnostic guide →Water dripping inside
Condensate drain, frozen evaporator, seal
Full diagnostic guide →Loud, grinding, clicking
Fan motor, capacitor, compressor, debris
Full diagnostic guide →Breaker trips when AC runs
Overload, startup surge, capacitor, low voltage
Full diagnostic guide →Fan runs, no cold air; hums but won't start
Capacitor, compressor
Full diagnostic guide →How to replace a failed capacitor
Match µF values, discharge safely
Full replacement guide →30A vs 50A, startup surge, generator sizing
Load math, breaker trips, soft start
Power requirements guide →Weak cooling at campground
Brownout, pedestal sag, EMS
Full diagnostic guide →Rooftop can't keep up
Quieter, more efficient, better cooling
Upgrade guide →Plugged in but nothing works
Pedestal, breaker, cord, inlet
Full diagnostic guide →Breaker keeps tripping
Overload, capacitor, weak pedestal
Full diagnostic guide →Some or all outlets dead
GFCI, breaker, wiring
Full diagnostic guide →Battery not charging on shore power
Converter breaker, 12V fuse, converter failure
Full diagnostic guide →12V not charging
Converter, breaker, battery connections
Full diagnostic guide →No 120V from inverter
Battery, overload, fuse, wiring
Full diagnostic guide →No power or trips when running
GFCI, breaker, overload
Full diagnostic guide →Pump won't run, runs weak, or won't stop
Fuse, tank level, pressure switch, suction leak
Full diagnostic guide →Weak flow at faucets
Regulator, filter, sediment, pump
Full diagnostic guide →Water on floor or walls
Fittings, pump, heater, tank
Water systems guide →No hot water from faucets
Propane, element, bypass, thermostat
Full diagnostic guide →Propane won't light
Propane, igniter, gas valve, ECO
Full diagnostic guide →Waste valve open but nothing drains
Solids buildup, stuck valve, hose blockage
Full diagnostic guide →Heater lights or heats then stops
Flame sensor, ECO, sediment
Full diagnostic guide →No water in bowl when pressing pedal
Supply, ball seal, linkage
Full diagnostic guide →Water backs up or drains slowly
Gray tank, P-trap, clog
Full diagnostic guide →Seasonal prep, structural issues, and system upkeep. Winterizing, roof, slide-out, leveling.
Freeze protection for plumbing
Drain, bypass, antifreeze, blow-out
Full checklist →Leveling blocks and setup
Uneven site, blocks, stabilizers
Leveling guide →Roof leaks, slide-out problems, leveling system
Guides in development
Check back →These tools help diagnose RV electrical, AC, and plumbing issues.
Test voltage, continuity, resistance. Essential for electrical diagnosis.
Best RV Multimeters →Measure amp draw without breaking the circuit. AC startup surge, load checks.
Best Clamp Meters →Verify AC capacitor microfarads. Diagnose hum-but-won't-start AC issues.
Best Capacitor Testers →RV AC Running But Not Cooling?
Check airflow restrictions and the evaporator freeze sensor. Restricted airflow is the most common cause of evaporator icing. Clean the filter first—monthly during cooling season. If the unit still freezes, check for blocked return air or low refrigerant (pro only).
This section tracks newly added troubleshooting guides and updates to existing diagnostic resources.
Top causes: dirty filter, low voltage, frozen evaporator, capacitor failure, or refrigerant loss. Check filter first, then verify voltage (108–132V). See our RV AC not cooling guide for step-by-step diagnosis.
Overload (too many appliances), weak campground pedestal, or bad AC capacitor. Reduce load first—stagger AC with microwave and water heater. See RV breaker tripping guide.
Empty tank (most common), blown fuse, air in suction line, or failed pressure switch. Check tank level and fuse first. See RV water pump not working guide.
Start at the pedestal: verify voltage, check breakers. Then trace inward: shore cord, RV panel, converter. Use our electrical troubleshooting guide and multimeter for diagnosis.