problems

ok so lastnight im driving down the road and my truck just turns off. it wouldnt start...i even got some guys to try to push start me and no luck. so i have it towed to my mechanic and this morning he tells me i blew a main fuse. i picked it up this evening, and everything seemed fine. as im coming up to a stop light i dump front passengers side and hit it back up and when i did that, the stereo turned off and back on. anyone have any idea what the hell is going on? it really annoying me since its my daily. thanks, matt