I'd call the dealer, or leaf through a repair manual at the library or at a book store.
It could be anywhere, in my last car, a jetta, the brake light relay, turn signal relay, flashers, clicking sound-generator //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif, were all built into the hazard light switch right in the middle of the dash.