You would be best to wire a relay direct from a fused line from the battery. The horn may have come with a relay. Relay can go inside the headlight bucket. FYI If you add anything like conventional Spot lights or heated gear you should have a relay for that as well. The ignition switch cannot handle additional loads without melting. The OEM light bar connector runs through the ignition and can cause a melt situation at some point even with the lower wattage OEM light bar bulbs.