Turn signals only work while parking brake orperated on '75, Strange issue. turn signals won't work unless parking brake is engaged. Options

[hawirick]

This is my first post on this forum, so forgive me if the issue has been covered before. I couldn't find it using the "search" feature. Probably common knowledge in the 914 community. Recently purchased a decent 1975 1.8 here on Hawaii island. There have been a number of small issues that I've had to deal with, but this one has me stumped. The turn signals only operate when the parking brake is engaged. Any ideas?

[hawirick]

Thank you for the prompt replies!
Answers to Spoke's questions:
Yes, the exterior turn signals operate but not in unison with the ebrake light. Only as directed by the turn signal switch.
Yes, the 4-way light work normally at all times.
With the car running or not, the turn signals work only when the parking brake is operated (the switch on the brake handle operated).

there is one additional symptom that I forgot to mention. When the parking brake is operated, there is a loud buzzing coming from under the dash, possibly from the flasher relay, which I believe is on the back of the fuse panel.