My $.02

I am having the same problem with my 87 Bert.

This past weekend, I removed the headlight switch (a p.i.t.a.)and cleaned it. It really needed it! So far, so good as far as the lights go.

I would give this a shot first.

Remove the front of the switch very carefully by prying off with a small screwdriver, and then remove the body by inserting the small screwdiver into release tabs on both sides. It does not come off from the back.

Good luck.

Joe F
87 Bert