Did what?
The car or vehical was too old.
Make sure connections are on tight.
Diagnose your vw for any small faults.
You may have overheated the engine or seized it.
wont crank or wont start http://www.kick-fix.com/nostart.html if it wont crank backup 1 page find no crank.
My 1999 Passat has 225000 miles and still going strong
there is a fuse for it check to see if it is blown
Check your altenator, fuel pump, and or starter.
what you need to do is take of +terminal from batt put key in egg turn to on pois leave it for 10 min reconnect + and away you go.
you must have the wires on the wrong way.
Have the same problem - 2000 Passat - they tell me it is the coils are the issue - will find out
Check stop light switch for misadjustment or defect