98 Accord 4cyl

Here is the problem:

1)I changed the battery (the procedure was correct, did not reverse terminals and there shouldn't be damage.)

2) Everything else works. but I noticed brake lights were out, fuse was burnt. changed the fuse in engine bay. Brake lights work

3) pressed horn, horn muffled for 1/2 second and went out. Cruise control stopped working, Brake Lights out again

4) Checked all plugs and horn relay. all connections are fine.
*Noticed that the STOP(Brake) fuse which I just changed is burnt again.
*Also tested that No Power is going to the horn relay terminal.

So, the problem occurs when I use the horn. It blows the fuse. using the brake lights only will not burn the fuse.

What's going on?? It appears those 3 things are related to that single 20A fuse under the hood, so i assume its the same fuse.

- Is the terminal supplying power to the 20A STOP light fuse overloaded? by what?
- Do i have a bad connection at the horn that keeps blowing that fuse?????