Hi I don't know if the attached schematic is the same as what your coach actually uses, but it might help you trouble shoot your situation. Does your interconnect relay actually operate via the BIRD controller or via the emergency start switch? If it does and you have a chassis disconnect latching relay (I don't know your coach) then you should see alternator voltage on the coach battery. Check for the 5 amp fuse shown on the schematic....lots of folks complain about it being blown.
You say that you have damaged the coach batteries because the alternator does not charge them. Is this because of many deep discharges when travelling, that shore power could not restore?
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