Dometic 2100 Awning motor issue
2009 Titanium 5th wheel with two 9100 awning units. Everything fine when i closed up unit in the Spring of 2014 and as usual removed battery during storage. When unit opened last month neither awning worked. Checked fusing and they seem to be fused together (green wires) at the battery, not in the fuse panel. Fuse was good. Assemblies "locked" at the side of unit and couldn't be moved. Called repairman. Told that one of the rocker switches was bad (each unit has its own), that the ground was bad (they have a common ground as i said) but that there was power to the units. Told that somehow the units shorted out because of the bad ground and that caused the burn out. Using a new ground did not cause either motor to function thus that are shot, I guess. To replace both motors is north of $800.
My issue is why this happened? It couldn't have happened during storage and either occurred while driving the unit to storage with the battery installed or when i first reinstalled battery this fall. There were no obvious noises etc, no smell.
I am told that a new ground can be established and new motors installed and all will be well. I am concerned as to why this happened and why it can't happen again. Why didn't the fuse blow?. Should there be an additional in line fuse placed if the above plan is followed or won't it help?
Any help or suggestions really appreciated.