electrical is baffling me-help!!

"Once I cleaned all that up- kept blowing headlights out- now with just battery on no key in ign, my horn blows and my dash brake light is lit."

You have an overcharge condition that may have melted the wires in the bundle under the dash together creating the problem with the horn and the brake lights being on. The bundle that carries the hot from the alt to the ammeter needs to be taken apart/opened up and looked at. I bet some wires have melted together and are cross circuiting.

I have dealt with this issue before and you need to correct the voltage regulator issue. Your grounding is the issue. And your regulator is probably shot now as well. When you rev it up to 2500rpm how many volts are you getting across the battery terminals/cables?

This problem will eventually cause the battery to boil and blow acid out the vents.

Run a dedicated ground from the battery to the regulator ground wire and terminate on the firewall under the ground screw. Also the bulkhead connection is a major source of problems...consider running a new wire from the alternator to the ammeter and bypass the bulkhead altogether.

.02

Mop