Most likely the problem is a bad ground in your headlight circuit.

This problem can usually be solved by cleaning the large ground connectors
that are located under the instrument cluster, behind and above the fuse
box, attached to the vehicle body.

Look to the right of the steering column and drop the fuse box down for
access. You won't have much room to work, but remove the various ground
wire connections and clean all the parts with fine sandpaper or emery cloth
and reconnect them.

I have solved the same problem on three Vanagons with the above procedure.

Michael J Vickey
vickrail@velocity.net

85 DblCab Vanagon Pickup
87 Syncro blue
87 Syncro gray
91 Westfalia Camper dk blue
93 Eurovan MV Westfalia top wht (FS)
93 Eurovan MV tornado red