An inverter beeping three times and shutting off typically indicates low voltage under load, overheating, or overcurrent protection activation. While your batteries show 12.8V at rest, they may drop significantly under load due to poor connections, battery degradation, or undersized wiring.
A lithium battery showing 20% but not accepting charge typically indicates a BMS protection mode activation. Try disconnecting all power sources for 30 minutes, then reconnect to reset the BMS before checking connections and charging sources.
While there's no direct plug-and-play replacement for the Atwood GC10A-4E with a gas-only tankless unit, you can upgrade to dual-fuel tankless heaters like the Girard GSWH-2 or Truma AquaGo. These maintain electric capability while providing instant hot water and better efficiency.
Dual purpose lithium batteries work for coach use but dedicated deep cycle lithium is better for house banks. Dual purpose compromises between starting and cycling. For RV house batteries, deep cycle LiFePO4 provides better value and cycle life.
142K miles on Cummins ISM 500 with Allison MH4000 is moderate mileage. These powertrains are designed for 500K+ miles. Focus on maintenance history and condition, not just mileage.
Speedometer stopping at 39 mph with working cruise indicates a stepper motor failure in the cluster. The motor can be replaced for $15-30 with soldering, or send cluster for professional rebuild.
The 2007 3-valve V10 does not need EGR delete like earlier versions. Focus on regular maintenance: Motorcraft spark plugs, synthetic oil, and transmission fluid changes. Engine is reliable as-is.
Everything RV owners need to know about the Ford 6.8L Triton V10 engine including common problems and solutions.
Spin-on trans filter kits allow easier changes. Mount in cooler line. Use as supplemental to internal filter. Multiple kit options available.
Girard II tankless requires different wiring than DSI tank heater. Run new 10 gauge 12V power with 30A fuse. Do not reuse old DSI harness. Follow Girard diagram exactly for proper operation.