car stereo head unit cutting out.

[G Beats]

hi all i wonder if you can help me, our alpine unit cuts out, it was doing it before i had a mp 6x9s and sub put in, it was working fine but recantly it cuts out and goes off, it does it when i turn it up as in shorts out and comes back on again, it does it some times when i put the heater on, i was thinking of takeing it to our local auto electrsion but i thought i try on here frist of all, could be the a wire going to the rocker cover as my brothers machnic mest this up with not putting the seal in the side of the rocker cover and it liked oil all over the engine there for this earth wire might need cleaning thats if there is 1 on there after fitting a webber carb cuss loads of the electrics go from the peco 1, we have recantly had a webber carb put on, can any 1 help please many thanx.