Easy to buy either one 12 volt buzzer and two diodes, or two buzzers ($3 each at Frys). Accessing the wiring might be a bit more work. Does somebody have an illustrated "how to"? Is the Turn-Signal relay located in a some easily-accessed place? I would prefer lower-frequency buzzers, so I (with substantial high-frequency hearing loss) can hear them better.
Drove the car for the first in 6 weeks, I was blnded by the flashing , and when I turn the radio down I could hear it
Had the same problem in several cars. Checked my hearing. Now, 2 hearing aids later, it is easily heard. Don't know if that is your problem, but hearing loss sneaks up on you so gradually, you'll swear your hearing is fine...till you get tested, and you won't believe the difference.