There will be a wire marked switched 12 Volt + or something of the sort. If you wire this switched 12V and the constant 12 Volt + directly to the battery your stereo will work all the time. Just don't forget to turn your stereo off.

Sean


99 XJ Sport 2 Door, 4.0L, 5 speed, all stock. Daily Driver
79 F150 Standard Cab Short Box, 400ci, NP435, NP205, 35" SSRs