I installed the Audiovox CC-100 on my St1300. I also used a vacuum canister that I got with the cruise from Murff's Kits. The cruise worked fine for about 500 miles then stopped working. After checking the electrical and the linkage I got around to checking the vacuum. I found no vacuum at the servo. What had happened is that the vacuum canister is now acting like is has a check valve in it. I switched the hoses and it now works fine again. I wish I had checked this sooner.
