Unless it was used in a pre 50's vehicle I would presume a 12 volt DC
supply, of course unless you had it in a commercial vehicle that could have
anywhere from 12 Volt up to 36 Volt. Nominal Vecicle DC supplies in the US
ar 12 Volt DC with the Red being Positive and the Black being Negative.
Suggest putting a series 5 amp fuse inline with the positive supply.
"Shane" wrote in message
om...
hi all,
I have a Motorola 2900 carphone that is no longer installed in the
car.
is there a way that I can power the phone up (without first installing
it in a car) to check that it is working?

There are a few wires hanging out of it - and i gather the red and
black are positive and negative respectively - but what can i connect
these too, to give it enough juice to power on, but i don't want to
damage it...

What voltage do one of these things run on?

thanks.