what does the collected wisom recommend ..
on an 85 vanagon ..
when there is 13.8 volts of charging ooomph at the alternator main terminal
...

and only 13.4 at the (  new  ) battery .

 I look for at least 13.8 volts at the battery.  13.4 is low in my opinion.
( I  like to see 14 something at the battery actually )
alternator appears to be a fairly fresh Bosch rebuilt.
The van's always started ..especially with the old somewhat worn 1.9.  (
manual trans ) ...

on my own 85 Adventurewagon I got at least a half volt more to the battery
with redundant batt cables added.
I don't want to do that to this van.

the 85 Vanagon has the  last year of the 'small' battery to starter cable of
course .  86 is considerably fatter.

trans ground cale looks good ..though I didn't take it apart.

I'll post another note regarding stater.
thanks !
S,.