LP2A Carrier Radio Installation

[Ian Hall]

G'day Everyone.
I am new to the forum, but I have owned an Australian LP2A Carrier (2930) for many years. 2930 is fitted with a No. 11 radio and an original wooden battery box (with "6V" on the terminal block) as per the manuals.

My question is how to wire up the battery for the radio ? The radio is 12V negative earth, while the Carrier is 6V positive earth. The manual for the No. 11 set shows a "Connector Low Tension" with leads to two 6V batteries which are connected in series to give 12V. In the Carrier manual, the only clue is that radio cable should be plugged into the inspection light socket. I assume the idea was that for charging the vehicle and radio batteries were in parallel, while for radio operation, the batteries were in series via some sort of two position plug. However, this cannot work with one being positive earth and the other negative earth.

Does anyone have a wiring diagram for the radio battery cables ?
Did this require the Carrier to be changed to negative earth ?

Regards,
Ian