Stereo power question (help!)

Do any of guys know which of these wires the stereo draws it's "amp" power from (constant or acc)? I noticed that this morning, the stereo would turn off if the volume was too high. I think it is pulling to many amps for the wires I hooked it up to, again, it's not a "high-powered" unit. Would a bad ground do this? I forget what I used for the ground, I think a screw in the dash.

Thanks for thinking about this - I hate electrical stuff!!