When I leave my aftermarket stereo on and turn truck off it drains battery overnight.But doesn't if I turn it off before I turn truck off it doen"t drain.Any ideas?
Is the power wire hooked to a fused circuit (key on/acc on only) <- if it's wired into the factory accessory wire for the radio there shouldn't be any power going to it.
Also if you hooked the memory wire and or the power (probably red/yellow or Red/orange depending on the manufacturer.) wire together and put them to a constant power source that's a bad thing.
Can you still listen to the radio when the key is off? Also a bad thing.