Onboard Systems Questions From Hacienda Heights Owners

Two separate systems share one coach, so the technician proves which side failed before touching a part. On shore power the 120 volt legs get verified at the transfer switch and the main breaker, then converter output is read at the distribution panel. If 120 volt is healthy and 12 volt is dead, the fault sits in the converter, the battery disconnect solenoid, the ground bond, or a fusible link at the bank. Diagnostics, scan and programming run $285 per hour with a one hour minimum, and that hour usually closes the question.

The converter steps 120 volt shore or generator power down to roughly 13.6 volts to run 12 volt loads and top the bank. The inverter runs the other direction so the microwave or a residential refrigerator can live off batteries. An inverter charger from Magnum, Xantrex or Victron does both jobs in one case. A murdered bank usually traces to a converter stuck in float, a charge profile still set for flooded lead acid on a lithium bank, or a parasitic draw nobody found. Inverter and converter repair runs $750 to $4,500 at the $260 per hour electrical rate.

A pause of several seconds is designed behavior, because the switch waits for generator output to stabilize before it throws. A total loss after that delay points at burned contacts, a failed relay coil, or heat damaged lugs inside the switch, which is common where a lug was never torqued to spec. The technician loads the switch and reads voltage drop across each contact set rather than replacing on suspicion. Transfer switch and shore power work runs $285 to $1,500. Arrive with both power sources usable so the switch can be cycled here.

A 30 amp coach has one hot leg at 120 volts, so about 3,600 watts total. A 50 amp coach has two hot legs and roughly 12,000 watts. Adapting down from 50 to 30 is electrically fine, since the coach still limits itself to 30 amps, but it adds no capacity. Repeated trips usually mean the roof air conditioner and the water heater element are running together, or a neutral connection has degraded in the cord or the inlet. The technician reads amp draw per branch and inspects the inlet contacts before anything gets quoted.

The bank gets a rested open circuit reading, then a load test, then a charge acceptance test with the converter running. Lead acid that will not hold near 12.4 volts rested, or that collapses under a modest load, is done. If the cells test acceptable but the coach never reaches full, the fault is charging rather than storage. Battery and charging system work runs $500 to $5,500. Sustained heat in a Southern California yard shortens flooded battery life hard, so a two year old bank failing here is not unusual and is not a defect claim.

More than most owners budget for. The converter or inverter charger needs a lithium profile, so a fixed voltage unit gets replaced outright. The alternator path needs a DC to DC charger so the chassis alternator is never asked to hold absorption voltage. Solar controllers get reset to lithium settings. Cable sizing gets recalculated, because lithium will accept far more current than lead acid and undersized wire becomes the weak link. Lithium battery upgrade runs $1,500 to $12,000 depending on bank size and how much of that chain has to be replaced with it.

The math starts at the load, not the roof. A residential refrigerator pulls roughly 100 to 150 amp hours a day through the inverter, so the array has to replace that plus every other draw on an ordinary day rather than a perfect one. Usable roof left over after the air conditioners, vents and a Winegard dome usually caps the real array size. The MPPT controller is matched to array voltage and current with headroom, then to the battery chemistry. Solar panel installation runs $1,500 to $12,000 plus, and the layout is confirmed on the roof before parts are ordered.

That is wet stacking, and it is usually behavior rather than failure. A diesel generator run repeatedly at light load never reaches combustion temperature, so unburned fuel and oil collect in the exhaust. The fix starts with a loaded run to burn deposits off, plus fuel filter, air filter, oil and impeller service. If the load test shows low output or weak compression, it escalates. Generator maintenance runs $400 to $1,500 and generator repair and overhaul runs $400 to $8,500 plus. The Onan or Cummins house generator is in scope; the chassis engine is not.

It involves a compartment that can carry the weight and vent exhaust safely, a fuel source, a transfer switch, and a wiring run back to the distribution panel. On an LP fed unit the gas train and regulator capacity get verified by the LP certified technician, because adding a generator can outrun the existing regulator. Onan and Cummins units are the usual choice and lead time on a specific model number can run several weeks. Generator installation runs $2,500 to $14,000, and upfit and fabrication turnaround is two to eight weeks once parts land.

The LP side gets verified first, so gas pressure, burner orifice, flue, igniter and control board all get checked. A blocked flue or a tired regulator explains that exact pattern often. If the cooling unit itself has failed, meaning ammonia loss or a plugged boiler, repair cost approaches replacement cost. A residential swap is not a drop in, since it needs inverter capacity, a larger bank and cabinet modification. Refrigerator repair runs $400 to $4,500, and the estimator puts both numbers in front of you before you decide anything.

Anything that opens a sealed refrigerant circuit, including roof air conditioner sealed system work and recovery, is EPA 608 certification gated. Regulators, gas trains, appliance conversions and pressure testing go to the LP certified technician. Frame and lift gate mount welding goes to a structural welding certification holder. ADAS calibration goes to the calibration setup. It does affect scheduling, because those queues are narrower than general body labor, so a certification gated line item can wait a day or two for the right technician and the right bay to open up.

Often yes, because inrush at compressor start is what trips a marginal pedestal breaker while a generator simply sags instead. A soft start module limits that inrush. Before selling one the technician reads start amps, checks the start and run capacitors, and inspects compressor windings, since a failing compressor pulls high start current for a reason no module corrects. Air conditioner repair and replacement runs $750 to $4,500. If the unit is aged and the shroud has gone brittle in the sun, a Dometic or Coleman replacement is usually the better number.

That symptom set points at the ignition and gas side rather than the blower. The technician verifies LP pressure at the manifold, then the sail switch, the limit switch, the gas valve and the igniter or electrode gap. A weak 12 volt supply produces the same complaint, because the blower never reaches the speed the sail switch needs to close. Suburban and Atwood parts are still available, though specific gas valves go backordered in stretches. Furnace and heating work runs $350 to $2,500 and LP gas system service runs $285 to $2,500.

Hot water with no cabin heat usually means the burner works and the distribution side does not. The technician checks zone pumps, the loop for trapped air, the heat exchanger fans in each bay, and thermostat wiring. On Truma units the stored diagnostic codes get pulled before anything is opened. If the burner is genuinely at fault, the nozzle, electrodes and fuel pump are the usual items. AquaHot and hydronic heat work runs $750 to $8,500. Webasto and Espar part lead times vary by model and can stretch the job by a week or more.

The gas train is isolated, brought to test pressure with a manometer, then watched for a set period. Holding pressure means the system is tight. Dropping pressure means there is a leak, and your appliance complaint may be a symptom rather than the cause. It is performed by the LP certified technician and it comes first because installing new parts on a leaking system is unsafe and wasteful. LP safety inspection runs $285 to $700, and a $45 hazmat and disposal charge applies whenever LP, refrigerant or chemicals are handled.

A pump short cycling with every tap closed is proving a leak for you. The system gets pressurized and held, then traced fitting by fitting, with a moisture meter run across panels and the subfloor wherever staining shows. PEX crimps, water heater fittings and the low point drains are the usual suspects. If a tank is cracked, welding or replacement is the path and access can mean dropping belly pan or pulling furniture. Fresh water system repair runs $285 to $4,500 and black and gray tank repair runs $750 to $8,500.

Usually a valve or solenoid rather than the cylinder, because a cylinder leaking past its seal generally weeps visible fluid. The technician isolates that circuit, caps the line, and watches which side holds pressure. Lippert, Power Gear, HWH, BigFoot and BAL systems all behave differently, so controller codes get pulled where the system stores them. Bring the coach powered and on ground level enough to cycle, since a system that cannot be run cannot be diagnosed. Leveling system repair runs $350 to $6,500 plus, and air suspension repair runs $500 to $4,500.

Sometimes, because both often share a roof penetration or a 12 volt feed that a failed sealant bead has let water into. The technician traces power and coax at the roof, checks the wall plate and the ground, and reads the display end before condemning either head unit. King and Winegard control boards fail more often than the motors do. Antenna, satellite and entertainment work runs $300 to $3,500 and backup camera and monitor work runs $400 to $2,500. Adding a roof and seal inspection at $285 to $900 is usually worth it.