Not disconnecting the ground is ASKING for trouble. It may not happen every time, but theres that one
Since the stock VW wiring routes all power for starter thru the switch, it usually burns up first.
__________________
1970 T1 W/MassIVe 2913cc RAT/?EFI? w/direct fire (very soon) and 915 trans
1962 SC 1776cc SP 944NA brakes, 993 wheels
VKG