I finally got the glass out. thanks for the link to the tech library at www.ifsja.org.
I got the gate apart and removed the regulator arm clips (not looking forward to re-assembly) and pulled the glass right out. I found a broker defrost wire - will solder back on. the regulator was in such a position that I couldn't get to all the bolts. so I had to remove the motor first and "risk injury" according to the haynes book. truth is, the spring pressure on the regulator arms isn't as much as they make it seem.
Anyway, I checked wires, breakers, and switches. the only thing that works is down with the rear switch. reversed the polarity to check that the motor would run in reverse and it did.