For 1990-2009 cars

Battery voltage is applied through CKT 1040 (ORN) to terminals 86 and 87 of the horn relay at all times. Pressing the horn switch grounds the horn relay coil. The relay coil can also be grounded on CKT 28 (BLK) by the remote function actuator (RFA) Module. The horn relay contacts close and apply battery voltage to the horns. The horns sound until the horn switch is released or the RFA module removes it.