NO POWER???

if i let my truck sit for a few days, it wont have enough power to start. its got a new battery and alternator. sometimes when i drive places it wont have enough power to start back up when i get out of the store. but sometimes it will. i won,t listen to music for fear that that might add to the power loss. does any one have a chevy 350 v8 wiring diagram? or if not can u help me figure out my problem?

is ita carbd mtoor? check your grounds first, you could have one thats broken and only hitting someitmes specially if you still ahve the factory crappy ass ground straps.

ya i just installed a new ground 4 gage wire, from the motor to the frame. and i dont have my subs hooked up(wires are all unhooked at the batter and the amp)