Headlight switch backlight dimmer blows horn fuse...???

So here is a new one. I can only assume the 2 are related as i didnt notice it before.

Drove my car for the first time in a while at night and noticed no dash backlights. I turned the knob on the headlight switch to turn them on, and low abd behold, it blows my horn fuse. (#8)

Only thing i have done recently is convert to a 1 wire alternator.

Independent wire to battery. Unplugged old voltage reg wires at firewall from the factory plug.

Horn works, and fuse wont blow until you mess with the dimmer knob.

Headlights, turn signals, indicators, all work.

Lowered column and pulled instrument cluster looking for pinched or fried wires....notta.