Thanks everyone,
This is in my 1979. It has the old-style GP. They do seem to work ok, I think the timer not timing out when I engage the starter my be related to the ignition switch

Glad I added that part about the power loss while driving. The cables are totally clean (cleaner than in the 1980 which starts right up with either battery).

I will swap out the ignition switch. I think that is the problem when I consider all my issues together.

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT