Whenever I blow the horn in my 2005 Honda 4-cyl EX the fuse blows, which kills the brake lights also. The horn does blow, so I don't think the short is there. Could it be in the steering wheel horn mechanism? Or the writing somewhere?

I tried to locate the horn relay but there doesn't seem to be one. Just the 20a fuse. Thanks in advance for any help.

 

I meant to say "or the wiring somewhere"

 

I think you are assuming there is only one horn but in fact, there are 2 horns, a high and low horn behind the front grill. I guess if I were you I would disconnect both horns and hit the horn and hopefully the fuse will not blow. Then I would connect one horn at a time to find the culprit. Don't ask me how to get to the horn because I looked through my service manuals and I could not find the removal instructions. I think looking at my Accord, that you would have to remove the front grill. I could reach the horns through the grill but that was the extent of it...could not see the connectors. Good luck and let us know how you do.

BTW, the black 4" x 4" box to the right of the fuse/relay box is the Relay Control Module.

 

I'll try that. Thanks.