RADIOS WITH 2 POWER LEADS

The red wire is typically connected to a fuse in the fuse box.  Choose one of these fuses:

If you want the CB to turn off when you turn off the ignition, then use the fuse for the AM/FM radio. If you want the CB to get constant +12V so that it runs even with the ignition off, then use the fuse for the brake lights.

After connecting the red wire to a fuse, turn on the radio and also turn on the ignition.  Now touch the black wire to various screws under the dash.  When the radio turns on you have found a ground screw.  Connect the black wire to that screw.

Alternatively, the wires can be connected directly to the battery.  Connect the red wire to (+) and the black wire to (-).

Cigarette plug: If you want to use a cigarette plug to power the unit, connect the black wire to the negative lead (side terminal) on the plug.  Connect the red wire  to the positive lead (center tip) of the plug.  Radio Shack sells a cigarette plug that is very easy to use.  Their part number is 270-036.

RADIOS WITH 3 POWER LEADS

The black wire goes to a chassis ground screw. The red wire goes to a switched +12 volt source, such as the fuse for the AM/FM radio. The orange wire is for the memory retention of your CB radio and should be connected to a constant +12 volt source such as the fuse for the brake lights.

With the radio wired as above, the radio will turn off when the ignition is turned off.  The orange wire will provide power to the radio so that it remembers the channel.

Cigarette plug: If you want to use a cigarette plug to power your radio, connect the black wire to the negative lead (side terminal) on the plug.  Connect both the red and orange wires together to the positive lead (center tip) of the plug.  Your unit will function properly this way but will not retain the channel memory.  When power is applied your radio will come up on channel 9.  Radio Shack sells a cigarette plug that is very easy to use.  Their part number is 270-036.