Ford Excursion I (1999-2005) Horn circuit

AIR BAG SLIDING CONTACT AIR CONDITIONING SYSTEM BLK WIRE CENTRAL JUNCTION BOX (BEHIND LOWER LEFT SIDE OF DASH) DIESEL DK BLU WIRE DK GRN WIRE FUSE 37 GASOLINE GRY WIRE HORN HORN RELAY HOT AT ALL TIMES LT GRN WIRE NCA WIRE ORG/ WIRE POWERTRAIN CONTROL MODULE (ON LEFT SIDE OF FIREWALL) SIGNAL RETURN RED WIRE SPEED CONTROL SERVO (IN RIGHT SIDE OF ENGINE COMPT) SIGNAL RETURN STEERING WHEEL/ SPEED CONTROL SWITCH VEHICLE SECURITY MODULE (VSM) (BEHIND LEFT SIDE OF DASH) YEL WIRE