Not knowing how the radio is programmed it most likely needs to see 12v on ignition sense to power on.
Ignition Sense Cable
Motorola supplies an ignition sense cable
and recommends that it be used with every
mobile
installation. The ignition sense cable allows the radi
o to be turned on and off with the vehicle ignition
switch, and allows the radio to “remember” the state
of the radio on/off switch, even if it is changed
while the vehicle is off.
• For radio ON/OFF control independent of the ignition switch, connect the red ignition cable (yel-
low for remote) (pin 25 of accessory connector) to “battery hot” at the vehicle fuse block (dash
mount only).
• For radio ON/OFF control via the ignition swit
ch, connect the red ignition cable (yellow for
remote) to “ignition” at the fuse block.
Note that for remote mount installations, the red and yellow leads are connected, not the red lead
from the rear of the radio. See
Table 2-1
.
The ignition sense cable uses either a 3-amp (P/N 6580283E01) or 4-amp (P/N 6580283E02) fuse.