The brain for the motorola phone. There is a white wire with a yellow stripe.
Notes: the hardness must be plugged into phone brain or the lead will be dead. Additionally, my CLK55 did not come with a handset in the center console. Thus when the ignition switch is turned the yellow/white lead sends 12 volts to the handset and if there is none it will then shut off after a few secs. You can keep the lead constant if you open up the center console and unplug the connector from the little wrench and emergency button...