Radio Shack 120-2130A - Manual (Page 6)

1. Connect the black GROUND (-) wire to a chassis ground, such as a metal
screw attached to a metal part of the vehicle's frame. Be sure that
the screw is not insulated from the frame by a plastic part.
2. Connect the red +12V to IGNITION wire (with in-line fuse holder) to a
point in your vehicle's fuse block that has power only when you turn
the vehicle's key to either the accessory (ACC) or START position.
This connection turns on the stereo when you turn on the ignition or
turn the key to ACC, and turns off the stereo when you turn off the
ignition. This prevents your vehicle's battery from being drained if
you leave the stereo on when you turn off the ignition.
3. Connect the yellow +12V to BATTERY wire (with in-line fuse holder) to
your vehicle battery's positive (+) terminal or to a fuse that
provides a continuous source of 12 volts.
This connection provides power for the stereo's components (such as
the clock), and continuous power for the stereo's memory when the
ignition is turned off.
4. Connect the blue/white AMP REMOTE TURN ON 500MA MAX wire to any
optional equipment designed to run from a switched source that you
want the stereo to turn on and off (such as a booster or a power
antenna).
This wire does not provide power to the components. It simply turns
them on or off. If you do not use this wire, secure it with a wire tie
and do not let it touch metal.
Note: The optional equipment must be designed for use with a switched
power lead.
Connecting Two Pairs of Speakers
If you are using both front and rear speakers, follow these steps to
connect the harness to the speakers.
Speaker Wires:
FRONT LEFT FRONT RIGHT
(White) + (Gray) +
(White/Black) - (Gray/Black) -
REAR LEFT REAR RIGHT