T Bucket Horn Wiring

The horn is a "stand alone" circuit.  It consists of an uninterupted  source voltage supply, a horn (or horns) a horn ralay, a horn switch, and wire. Assuming your T Bucket is chassis ground, you can simplify your wiring by not using ground wire links. Meaning: "hot" or B+ wiring only. This is also assuming that your relay & horn(s) are base grounded and bolted to the chassis or engine. 

This circuit does not show a fuse for simplicity, however a 15 AMP fuse is recommended and would be placed between the battery B+ and the relay. Also note that the horns are parallel wired. Because the B+ is a direct connect to the battery, you can hook the "hot" wire to the primary post on the Starter Relay. This is a common practice. Another method is to make a "junction (fuse) box" that distributes "fused" Hot wires to different loads.

T Bucket Fuse Block in "stand alone" circuitry

This wiring setup is for "stand alone" operation, meaning that all these devices will operate at all times. The ignition key is used for "locking" the ignition only. You may place the Ignition switch between the the battery an the fuse block, thus "locking" all the devices.  The wiring on the ignition switch for "dependant" operation would be:

BAT: connects directly to the battery or "hot" lead on the Starter Ralay

ACC: connects to the fuse block(with the other components)

IGN: connects to the ignition components