toyota pickup probs

hello, i went to fix a kenwood tape deck in a late 80's early 90's toyota pick up. the previous owner did a hack job and the guy i was fixing the radio for did as good a job as the first guy.  the guy ran a wire to the fuse box which is a switch'd power supply and connected both the acc and main power wires to it to power the deck.

i went in and used my meter to find other wires. i found 2 constant power wires. one was connected to a lone connector and the other was in the mian harness (RED / black i beleive)  i doulbe checked all the other wires and they were right. thought i was done untill i realise that when i put the power wire to the deck with the acc it's like the ignition comes on. and the what was switched power become a constant from the fuse box...anyone know how this might happen...i'm thinking soemthing in the deck...but right now, i'm lost...also, i dont know if it means much but the clock is on and lit up constantly.

Disconnect the switched wire, also ensure the wire you have as constant is indeed that, and not just a wire that rests at positive voltage (like a dome light wire).  Test the wire with the door open, and see if it's still hot.  Check for a white wire at the ignition switch it should be your constant, and remember to use a fuse.