Thanks for all the tips guys. We had it running within 20 minutes of me getting there. I can't say for sure exactly what the problem was, because on my way down with new batteries I had him disconnect the old ones and begin cleaning up all wire ends with wire brush.
I installed a new chassis battery first, and with no coach batteries connected it started and ran fine with 14.2 volts at the terminals. I then installed new coach batteries and was showing 14.1 there.
Next, I opened up the water fill ports on the old 6volt batteries to take a look inside. Completely dry and looked like a science project between the plates. So I'm pretty sure that was the load that would stall the motor upon pedistal disconnect. I imagine the converter has been working overtime trying to force a charge into these batteries for a year or two.
We made it home safely. Thanks again for the tips.
