I have done the SDS firmware hack and now the connectors for the back of the RNS-E, have arrived today.
I understand, from an earlier thread, that I connect from pins 1 & 7 from the RNS-E "C" connector to the existing mic cable in the 17 pin plug in the passenger footwell.
I have some stereo headphone cable which is 2 core (red/black) shielded which I intend to use.
The question is do I use the red for +ve and the black for -ve and if so does the shield of the cable need to be earthed? Or do I use the shield as the negative and the red as +ve (and not use the black at all).