yes sometimes there is either one in the back of the head unit or there could be little glass fuses inside the casing but i doubt it will be the latter, your best bet is to get a multi meter on the loom and check you haven't burn't the cable out or something you could of even burn't the unit out if it was connected properly, i'd first connect the red and yellow wires to the positive on the battery and the black on the negative if it still don't turn on then you deffo no it's the unit not car wiring