VXA7211
INSTALLATION GUIDE
PAGE 2 of 2
AIR LINE INSTALLATION
Connect one side of the airli
ne to the compressor’s air exhaust port and the other side to your horn’s air
intake port.
For optimal performance use the shortest length of airline possible.
IMPORTANT
: Do not make any sharp bends or kinks in the tubing which could alter the sound of the horn or
even restrict airflow.
ELECTRICAL CONNECTIONS (FACTORY HORN SWITCH)
For vehicles with a two-
terminal factory horn, transfer the wires to the compressor’s terminals. If the horn
doesn’t sound even if the compressor motor turns on, simply reverse the wires.
For vehicles with one-
terminal factory horns, make sure you transfer the wire to the compressor’s positive (+)
terminal. The negative (-) terminal uses a 16-gauge wire or heavier to connect to ground.
IMPORTANT
: When connecting the compressor to your factory horn switch, the use of a relay may not be
needed because your vehicle’s circuit may already have one.
ELECTRICAL CONNECTIONS (NEW HORN BUTTON)
In a dry location, install a 4-PIN relay (not provided) making sure that terminals face downwards near the
horn.
Using a 16-gauge wire or heavier, connect PIN 87 of the relay to the positive (+) terminal of the compressor.
Connect PIN 85 of the relay to the horn button (not provided). The other horn button terminal is attached to
any rust and paint free metal to ground. Connect using an 18-gauge wire or heavier.
Connect PIN 30 and 86 of the relay to the battery, alternator or other positive (+) of 12-volts. Make sure the
wire used is a 16-gauge wire or heavier. Use a 20A fuse (not provided) to protect the electrical circuit.
