Multi Plus II installed in my fifth wheel in August 50 amp shore power along with two 300 ah battery’s , everything working as it should, shut down for winter storage for a couple weeks. Went to check on battery power still at 99% plugged into shore power, checked power into Multi plus 12.6 volts on the battery side 120 volts on the each leg of the shore power in side, turned on switch and nothing , led lights flashed once but nothing works, not sure what to look for, any suggestions would be helpful.
Disconnect shore power. You measured 12.6V, ok. Confirm at the inverter terminals, not only at the battery posts. A loose lug or bad crimp can show voltage but drop under load otherwise unit won’t boot.
If it boot without shore power then you have a problematic AC in connection.(Shore power)
sorry I should have said this is checking power at the inverter and it was also plugged in on shore power, 50 to a 30 amp adapter (system is set for 30amps) and checked each leg at the inverter and they were 120 volts , also rechecked all connections all were tight, the strange thing is everything was working fine a month and half ago, not sure what I’m missing.