Your altenator in the van is not working to produce voltage to run the van
after you disconnect
from your jump car ( source of voltage, remove the source it dies) and your
battery inthe van is not holding any charge. Again a source voltage is
removed  when you disconnect.

Thake out your altenator and battery and go to a local flaps and have  them
checked. Most flaps will do it for free.

Jim Morgan 86Gl