This Preliminary Information communication provides information to the technician about vehicles that may have a radio backlighting will stay on even after the ignition has been turned off and the key has been removed for several minutes, eventually the battery will drain. Technician may find following fuses F23DL F22DL F30DL F31DL F32DL with the ignition key in the off position to have voltage. Technician should not replace the Transfer Case Control Module. Technician will need to install a diode, part number 12112422, across the coil of the solenoid. It is important that the striped end of the diode be connected to the positive terminal of the coil and the other end of the diode be connected to ground.