DDK - Die Deutschen Klassiker

Help
Just drove 15 miles on unlite country roads,raining with no main or dipped beam and wipers. Was just putting it in the garage and the lights came on and now the wipers work also. Think it must be a bad earth connection but where.
Any body got any ideas two seperate ciruits so would nt think its on the feed side, but could be wrong
THIS IS ON 1973 2.4 911
Hopefully many thanks
Richard

first place to check is the fuse box (which you've probably done) check the fuse is held tighlty and the wires are properly connected. The wipers and lights don't have the same earth so check the power side first.