Personally I would not install additional horns to existing wiring without a 12 volt relay wired to the battery. Will soon be installing 3 new AC Delco horns wired to a relay, triggered by the stock horn wiring. Have done this to previous vehicles, including a motorcycle. The 3 different toned horns produce a diesel train sound. Loud and awesome. These are the same horns used on a 1996 Cadillac Deville. Each horn draws 3.5 amps (11 amps total). Instead of accessing stock horn, hope to identify and trace wiring from fuse or horn ring? Place a switch at that location to be able to switch between stock and the 3 new horns. This way when inflating the tires I can switch it to stock and not go deaf when reaching the proper psi. I have yet to have to inflate tires but read that when reaching proper psi the horn is triggered. The horns are AC Delco D1922C, D1923C, and D1925C, which produce a F- low, D- super low, and A- high note. Available at any online auto or amazon or Walmart. If you love an attention getting train sound that takes up little room, and draws very little power, this is it! Will provide details on install after completion.