Could I check my use of diodes in the following circuit?
I'm wiring a new car stereo head unit into my motorhome (RV).
I'm going to use most of the standard radio harness connections. However I would like to run the 12V power from the leisure battery so we can listen to the radio whilst parked up without the engine on and not drain the main battery.
The question I have is around the wire going into the head unit from the ignition circuit to turn the radio on when the ignition is on. I want to add to this a separate connection from the leisure battery with a separate switch. I want the radio to come on when I either turn the ignition on or switch the leisure battery switch.
I was going to use two diodes so that the leisure battery didn't interfere with the ignition circuit.
Have I got my wiring correct?
Will single 6A diodes do the job?