The prior owner installed an aftermarket radio and disconnected all the Harley plugs.

Am assuming one would need a special aftermarket radio design to connect to those plugs and be able to utilize the hands control?

which radio is made to receive such a signal?

the radios that I have don't have any extra wire inputs to allow for that.

Which radio is known to work with Harley's?

I heard some dual radios are made to be control

 

You only need a control module to fix that issue. I like the biketronics unit, but there are several that do the same thing.

 

Axxess Aswc-1 Steering Wheel Control Adapter

Scosche HDSWC1


just a couple