Iris, there are many ways to skin this cat, and the
powered interface Part #: 2342 is just one of them at $99. I use a
battery eliminator that costs less than $15 off Ebay to provide power to the radio. Power is from a switched circuit on the Fuze Block in the tail of the bike. The Autocom comes with a 5-pin lead to connect to the radio and this is connected to the
Kenwood Interface Lead #2368 or 2369 for $22. So you can put together parts for under $40 that do the job of a $100 part.
Also, you say yours is broken. What is going on exactly? Are you using a PTT #2356 (push to talk) from Autocom? It comes with a push button and lead that plugs into the radio/Autocom interface. This is the most important part you can get to have clear communications to get away from the undependable VOX.
I recommend you call or PM Fairlaner (Richard) first, as it seems he has all the parts and can be very helpful (believe it or not). If that is a dead end, call
Autocom Direct the USA distributor at 866-951-5550 and let them know what you want. I outfitted most of my parts through them. BTW, you can spend an insane amount of money on this crap if you're not careful.
Good luck, and don't hesitate to ask any question. I'll look to see if I have an extra radio interface, but I don't think so.