[Mgs] positive to negative ground

Paul Hunt paul.hunt1 at blueyonder.co.uk
Tue Aug 25 05:50:11 MDT 2009


Installing the opposite polarity radio is tricky as the cases are almost
always at ground potential and would have to be insulated from the body of the
car.  That would still leave any metalwork on the front of the radio likely to
be live, and awaiting keys or whatever to short it to other metalwork in the
vicinity.  Radios produced around the time of the change had polarity change
switches or plugs fitted.  An accessory socket (cigar lighter) is much easier
to mount insulated from the body to be used for negative ground devices but
where you want the car to remain original i.e. positive ground, but an
alternative for those is to wire the socket as it is supposed to be i.e.
centre pin to live i.e. negative and body to ground i.e. positive then use a
full-wave bridge rectifier in a little insulated box between that and your
negative ground devices.

PaulH.
  ----- Original Message -----
  ... I have a 1954 MG TF. I may want to install a radio and put a 12 Volt
power socket for cell phone
  charging etc.


More information about the Mgs mailing list