Um before I put my foot in my mouth... Im not quite sure what your asking... You want to disconect your head unit? or your alarm? Iether way they are both hooked up to your batery....Uh... the one uder the hood! Like next to the motor, were you put oil and coolant and such... The alarm system may be hooked up to the alternating curent generator.... Ok now I look like an ass... Go at it guys