Got the trailer back home yesterday and made some progress. So a couple of things were kind of dumb...
1st thing, checked all of the wiring and one of the previous owners apparently thought that the twist on wire connectors are appropriate for an automotive application - WRONG!!! Tightened up the connectors on all of the twist connectors that were falling apart (These are all getting replaced this afternoon).
2nd thing, traced the wires back to the power junction and the power to the furnace was on a different circuit than labeled and had no fuse. Put in a new fuse and instant heating!
The thermostat doesn't actually have an on/off setting, so I have ordered the Emerson single stage 1E78-140 thermostat, so I can turn it off at the thermostat. There is also an on/off switch on the side of the furnace tucked underneath the cabinets, but that was actually turned on. Apparently a previous owner thought it was better to just pull the fuses on anything he didn't use - like the furnace and propane leak detector.
I did also go through the exhaust/intake ports and cleaned out the big 'ol wasp nest that had apparently been abandoned a while ago as well. So hopefully I should have good air flow as well :D
Going to dive into the water heater issue again after work today and start by cleaning all of the terminals as suggested by another person on here. Anyway, happy to have made some progress and thanks for the good advice on here folks!
