Hello, The Yellow is constant 12V for the clock, memory and other settings, the Red is for switched 12volts, and the Black (ground) can be run straight to the battery, but should be run to a grounded metal part of the chassis of the vehicle as close as possible to the radio to eliminate the chance of it humming.
Firstly let me apologise for not responding earlier but I was called away on a family matter of importance. My question is not totally answered. The radio will not be "switched". In that case which wire do I connect to the positive lead, the red or the yellow, or, in this case , do I connect both to the power source ?
Hello, If you don't have a seperate circuit to switch the radio on and off, then you would connect both the red and yellow wires to the constant 12V source, and use the power button on the radio to switch the unit on and off.