It doesnt need a wiring harness
The steering angle sensors are a bad design that let's in water and causes the sensor to loose communication with the system.
The issue was that Honda had the procedure for installation and registration incorrect. They weren't having us set the sensor to "zero" or center when registering and the system would freak out due to the angle reading being way out of line from what the SCU was ok with.
They've since fixed the procedure and other then installing the sensor, it's a 10 minute job to reset the center.
As far as the connector goes, any technician should be able to repair a connector with new pins. There's a bulletin with part numbers for several pins, seals and connector housings available.
As far as a wiring harness goes, if ypu couldn't have that done in 2 maybe 3 working days (so 24hrs tops) then you need to find a new job. I've swapped a 4 seat frame in 3.5 days.