Join Date: Jun 2005
Location: Dobbs Ferry, NY
The antenna should have 3 leads: a ground, a constant 12V, and the control wire attached to the radio.
The antenna control wire that is connected to the radio supplies power to a relay attached to the antenna.
When the radio is turned on, power is fed to the relay (from the radio) via the red/black control wire, the relay switched is closed, and the antenna extends. When the radio is turned off, power to the control wire is cut off (or the wire is grounded), the relay switch opens, and the antenna retracts.