Seems it is time to check the horn contacts for corrosion, it has been on-again, off-again over the past few days. Now I wonder where the hell that's located?
Tx. It's been 5 years since I did the Hella brackets.... I almost forgot that's where it is.Had a similar issue on my 07.. the horn wouldn't be as loud.. its like half loud.
Horn on the 07 was located front driver side by the fog lights.. I was able to reach through without removing anything.
Good luck