The LSS module has three power wires, Red+12, Black-12/Gnd and yellow. The yellow wire is a wake-up wire for the module. It can be connected to +12 directly, to +12 through a switch or connected to the yellow wire coming out of the HDS unit. If connected to the HDS yellow wire, then the LSS module will power up when the HDS is turned on. If connected directly to +12, then the module will remain on all of the time which will drain the battery during storage.