good point. Here are some observations that I have:
1. Batt voltage at NO load is 12.4V
2. When ignition is at "Start" position and X27 connected, dash warning lights dims and stays dim even after ignition switch returns to "RUN" position. It takes a while before dash warning lights return to normal illumination. Starter does not spin.
3. The same is observed when X27 is disconnected. It looks like other components are drawing current via X26 even if the starter is disconnected at X27. Does this symptom suggest another possible problem?

I think it may help diagnose the batt if I measure the voltage ( with load) accross the batt term when doing #2 and #3. what do you think?