Buzzing from clocks when main beam is switched on?

[GrahamB]

I have been tampering with my bike for the last 2 weeks, some good progress, some not so good. One of the many things I "tried" to do was wire in a gear indicator but after several attempts at mounting the sensors I gave up. Managed to blow the headlight fuse whilst I was messing but replaced it & all seemed well. This was last week. Now the bike is complete again, every attempt at switching from side lights to main beam results in dim indicators coming on (all 4 from memory), some dash lights also coming on dimly & a strange beeping/buzzing sound from the clock/dash area.  Spent all day on it today as work is slack but it was getting late when I got to this stage so thought I would try you folks for inspiration before I tackle the problem tomorrow.

Any ideas what I've done peeps?