Got the HD kit yesterday and started going through the instructions. Spent $15 at Kinko's copying and enlarging the various wiring diagrams from the back of my 1993 service manual. Seems that the harness that HD included in the kit has a couple of wires that aren't used in a normal cruise install, so I disassembled the harness and removed them thinking that I might need the wire later. Sure enough, since the FLHS does not have a brake relay to tap into off the cruise harness, I used the extra red wire to tap into the brake switch instead. Should work fine as the only function of that wire is to send voltage to the module when the brakes are applied and turning off the cruise control. I will need a toggle switch like was used on the FLTCU because the kit includes a rocker switch for the FLHTC. Tomorrow I'll go under the instrument cluster to see what is (or isn't) there.