Today I have finally been able to solve the problem with the acoustic signal of the flashing, and it has been fast and easy. The solution was to change the intermittency command handle. What produces the sound is housed inside the hand of the handle and it is necessary to change the entire piece. Displacement to scrapping, two minutes to disassemble and two minutes to reassemble it, so easy. I hope that if someone has the same problem in a 2004 focus serves the solution. Greetings