Battery positive voltage is applied at all times to the horn relay terminals 85 and 30. Pressing the horn switch grounds the horn relay coil on CKT 28 (BLK). The relay coil can also be grounded on CKT 28 (BLK) by the Dash Integration Module (DIM). The horn relay applies battery positive voltage to the horns on CKT 29 (DK GRN) when energized. The horns sound until the horn switch is released or DIM signal is gone.