head unit install question

i took my pioneer cd player head unit out of my corolla, because im trying to sell it.  i've been trying to install a cheap cd player in its place.

but when i got it going,  it overheated very quickly, to the point where a tiny amount of smoke came out of the head unit (!!).  The problem seems to be antenna cable, when that is disconnected the unit doesnt overheat.  this same problem happened on a daewoo head unit i tested.  the thing is, the daewoo unit never used to overheat like that.  the pioneer still runs okay - i think.

im pretty familiar with the car and i know the other wiring isnt at fault.  does anyone know what could be the problem?

i dont know how the antenna cable works, i assume it simply runs to the antenna itself and the head unit powers it to receive a signal?  could it be somehow drawing too much current?

thanks.

hi,

when you switched the headunits, did you also switch the wiring harness?  You may  of had a head unit that had more power running to it then the previous one, or there is a possibility of a mis match in wires that were connected, or one of the wires may be damaged or slit open which would cause it to either spark or smoke.