My headlights are playing up!! They stopped working altogether which was due to corroded connectors which I replaced along with new bulbs. Dipped works fine and main beam works but sometimes stops working momentarily or sometimes completely as you are driving along. Could it be a relay please?
I had a similar problem with mine. The spring loaded contacts had been flattened over time so I bent them with a small flat head screwdriver so they made a firmer grip on the spade connector. Problem solved.
There’s no wear in the stalk is there? In that the motion of the car is causing it to wobble and momentarily break the circuit. Have you tried moving the stalk by hand to see if you can replicate the problem? When main beam switches off, does the high beam indicator turn off too and does the dashboard illuminate go out?
Thanks for the advice. I’ve made separate earths for each light, checked the connectors and looked at the stalk. The strange thing is that the main beam was only working with the ignition on and engine running but now it’s reverted to working without the ignition on. I’m hoping my “playing around” has cure it - time will tell!!