you bring up a good point..one that i thought i already had worked out,now rethinking things. the feed for the coil puts out a signal and on the last C.C(vacume-audiovox) i used that for my speed input (same st1100). this i belive is the "pulse per mile" (square wave) input they are requesting for the right dip switch combo. i belive i can use the same input to control this newer cruise control. i am planning on calling the tech help line at rostra tomorow with a few other questions.. and thought it unreasonable to assume that they should know this peice of information, and i should have it ready, in case it comes up. for what it's worth- rostra and audiovox are NOW the same company and for the time being they are marketing this under both names. the actuall unit carries the rostra name and is called "global cruise electronic cruise control"... only the packageing and pricing differs i belive you'll find the audiovox being the cheaper. the pettigree of the current audiovox vacume units are unknow to me.