hu wont turn on

i am attempting to install an alpine 9831. I bought a wiring harness and i soldered together all the wires so that i can just plug in the headunit to the car. it wont turn on. i am sure that i connected all the wires correctly, and its not the car fuse becuase i tried the stock hu again, and it worked. the hu has a small fuse on the power cable, but i doubt that would have blown already, considering i am just installing now. i checked the alpine manual and all it said is to make sure that you have hit the reset before installation, i have done this. i have no power what so ever to the headunit. what the hell is wrong?

If I was you, I would double check ALL wiring and fuses again

if all else fails try conecting it directly to the battery and see if it turns on. If it doesnt you know you got screwed. if it does track down your wires.

actually, i had figured it out. my wire harness was providing a black ground cable, however, once the harness connected to the car cable, it essentially was a dead end. my car cable doesnt actually have a negative lead, so i desoldered the ground and attached it to the chassis. it works now, and it was an obvious problem. i dont know why i didnt think of it sooner.