2011 Prius Horn Not Working Diag Help Please

Very doubtful I will get a response in a timely fashion but will put it out there that my horn, along with driver's master window controller, heater fan speed buttons and radio display are not working properly. I carried to my local Toyota dealership and they told me that each part needs replacing before the next step in the troubleshooting process moves forward and I know in my gut that it is a short wire somewhere which connects all of the points for the current defects. I can live with the nuisance of these things however need an operable horn for registration inspection. HOW CAN I BYPASS WIRING HARNESS FOR HORN ONLY? for the meantime while the wiring harness gets better inspected? I fear mice have chewed on a wire somewhere, possibly, but finding the wire and location seems pretty hopeless with my limited knowledge and understanding. Along with not being able to access a proper repair manual, diagram or schematic.

The horn started out working sometimes and not other times, along with the driver's side master window controller started acted wonky, working sometimes and then not. That same gremlin worked itself to my heater and ONLY the buttons that adjust the fan speed are not working (auto-mode allows lowering of fan speed). The factory CD/radio display also started going wonky with sometimes showing nothing or a bunch of weird symbols and asterisks. Personally, I think things plugged into the lighter adapters (cellphones and Bluetooth radio connected to AUX audio input in center console) was the first to start acting up, I believe if memory serves. That audio input crackled a lot with older Bluetooth unit and still does but there's no direct evidence that when the AUX audio input crackles, the radio display acts up.

As a side note, I've never learned how to use the steering Bluetooth phone option so can't speak on it's defectiveness but have put over 100,000mi on this car and I want to keep it. I find value in it.

A year ago, about summer of '23, I changed the window controller and it worked but quickly went bad and started working worse than before so I put the OEM back in. The problems being with OEM, unable to roll up the rear windows and when rolling the front windows up, they roll down randomly as if the safety switch is triggered. The replacement unit only controlled the driver's window so that was a waste of $35. Along with the $135 to get the diagnostic done by Toyota for them to tell me each of those components are bad and/or that's as far as they can test without replacing each unit and going from there. Not to mention no guarantees with no exchanges or returns on electronic components.

My question for this forum and this thread, beyond how to rewire the horn to bypass current circuit and act independently, is how do I find the wiring schematics and diagrams for my 2011 Prius IV? I went to the website in the thread and it didn't prove useful for tackling this problem. My gut is telling me there's a wire that connects all of these points, possibly a fuse somewhere (which if known where would help troubleshoot) that is blown that belongs to that particular array of wiring that effects the horn, driver's side window master controller, the radio display and solely the AC/Heater fan speed. There could be something else on that same wiring array not working that I am simply unaware of, too.

If anyone can offer help, I'm eternally grateful. I don't know if the lighter adapters for external devices, an exposed short or burnt wire in an array, hungry pests, or something has really devastated my life being I must renew (actually change states) registration this month.