Hi,
I have two electrical gremlins that just popped up and would like some advice:

(1) When repeatedly turning on the high-beams (lights up or down) the horn will go off
(2) The left turn signal will cause the rear break and signal lights to alternate on an off.

Regards,
Dan

If your car was working fine and this just started, My guess is the turn signal switch in the steering colum is the problem. The brake lamps should not be electrically connected to the turn signals. If it is the rear parking lamp flashing, it could be a bad bulb in front.

what year is your car?

I have a 1975 and this just started happening. Although I have not driven the car nearly as much as I have in the past, in fact I'm round its first 500 miles since the new engine.

Don't know about the horn/dimmer although they seem to be very close to each other in the steering column.

About the turn signal/brake light, it might be good to check all the grounds around the rear lamp assembly.