...a shoe was lost. In this case, a fuse was the culprit.
The converter was installed and I plugged into the 30 amp outlet. All was well until Sunday morning. The refrigerator light still didn't work and it wasn't cooling, the water heater DSI (Direct Spark Ignition) didn't light, and the steps didn't extend or retract. The guys in the shop don't work on Sunday. I checked the fuses under the refrigerator, replaced one and flipped the circuit breakers with no success.
So I returned on Monday to find out what went wrong. Chris looked at the other bank of fuses under the hood behind the batteries. These are the fuses I can't see and are close enough to other wires for me to leave alone. The wiring connection was corroded and power was not reaching from the batteries to the converter. He used sandpaper on the connection, replaced the wire and fuse, and the refrigerator worked. So did the water heater. The steps, however, are still not functioning. The power step fuse looks good. It was late, everyone was tired and I plugged in again for the night.
Reminder: check fuses and condition of connections regularly.