Sounds like it was wired wrong, there should be a wire for 12v constant and a wire for 12v switched so the deck turns off with the ignition, the constant is only for the memory settings etc. Maybe they were reversed or something? Did the light on the volume **** stay on since day 1 or did that just start happening recently? But to be totally honest, I would stay away from Dual from wal mart, you can get much better decks from like Kenwood, Pioneer, Jvc etc. For under $150 and they are so easy to install as well, then you know it was done right.
06 Sport Dark Shadow Grey 4.0l
K&N drop in, Scanguage II, Explorer Domelight and ohc
Magnaflow 2.5" catback, metal tailgate handle from graniteguy
Ultra Mongoose 178 rims 16x8 with Toyo Open Country AT II.
Cranked torsion bars
Kenwood head unit, 6.5" Kenwood Excelon components, Rockford Fosgate 10" sub, all powered by 2 Alpine amps.
coming soon: Bilstein shocks , Wet Okole seat covers.