This is my first post and I have learned much over the past few months here. The 2007 Prius horn is wimpy and I bought a high low air horn to add and not to replace the existing one. I could install a momentary switch on the dash panel but want to have quick access to the button. My steering wheel controls has an empty section because I don’t have the navigation and handsfree phone option. I recently replaced the clock spring and realize there are unused path ways. Are there diagrams that shows the wheel side and column side pin outs for the connectors? If none exists then I’ll use a multimeter to test for open unused pathways. Thanks!
Welcome to PriusChat!! There are digital copies posted in the forum, and some members will host or send them as well. The advanced search feature works. Try this : https://priuschat.com/attachments/prius-wiring-pdf.33780/ If you do test, please post anything learned. Please use this thread to document this mod so that others can learn, and include lots of pictures, as everyone loves those. FYI : you're moderated until you've posted 5 times.
Tap into the existing horn connection with a 4 pin relay. I did this on my motorcycle with a Stebel Nautilus air horn. Works great and no codes. Pixel 7 Pro ?