Again, the wire colours would help. It isn't easy to see the colour coding from the photo. If the wires are brown/yellow and red/yellow, it would be for an external fan. Does your head unit actually have a fan, it appears for Audio 30 at least. The unit would work without the fan wires connected as long as it does not get too hot. But Audio 20 may not have a fan at all and then the wires are there waiting for another head unit.