Another typical 1.9 problem is a bad connection at starter (the big +
connector)...
Basicaly, the starter serve also as a connection between the battery and
ALT, i'm not saying that "is" your problem but the symptoms are exactly the
same when the connection goes wrong.

It take 2 minutes to check that 13mm bolt and connectors surface.

who knows, you have been uner the van for the pump so maybe!!!

Ben