VXO8210/3311B2
INSTALLATION GUIDE
PAGE 4 of 5
ELECTRICAL CONNECTION
ON-BOARD AIR SYSTEM
The red wire of the on-board system coming from the bottom of the tank should be connected using the
provided fuse to (+) 12-volt power source.
IMPORTANT
: To prevent the compressor from over running and
possible damage due to an air leak,
connect the compressor’s red wire to a power source in the vehicle that
only gets power when the vehicle’s ignition is on. Recommended connection points are: windshield wiper
motor, blower motor or an accessory terminal on the fuse panel. Make sure to use wire that is as heavy as the
wire of the compressor.
The black wire of the on-board system coming from the bottom of the tank should be connected to ground.
The ground connection should be rust and paint free.
Your compressor is now set for use and will turn on automatically when air pressure in the air tank falls. When
air pressure reaches maximum PSI, it will turn off. If the compressor fails to reach the maximum air pressure
of the tank, which is the Pressure Switch's cut OFF pressure, check all air connections for leaks. While the
compressor is pumping, use soapy water or any bubble solution to perform this check. In case the leak
remains after tightening, re-apply thread sealant.
IMPORTANT
: Never touch fittings, connecting tubes or the air compressor with bare hands either during or
shortly after use.
HORN (SOLENOID)
USING NEW HORN BUTTON
Join one wire from one solenoid with one wire from the second solenoid, then connect it to the positive (+)
terminal of the battery, alternator, etc. This circuit should be protected using a 20A fuse (not provided).
Join the other wire from one solenoid with the remaining wire of the second solenoid, then connect it to one
post of the horn button. The remaining connection of the Horn Button must be connected to ground.
USING VEHICLE’S HORN SWITCH
First, determine the switch’s polarity. The horn of most vehicles sends a negative (-) signal which can be
confirmed by connecting one of the probes from an ohm meter to the wire of the horn while connecting the
other one to ground. The meter should be at zero. This proves that horn circuit is negative (-). In case the
meter reads anything other than zero ohms, test for voltage between the wire of the horn and the ground. A
12-volt reading would mean a positive (+) horn circuit.
Once you know the horn circuit’s polarity, join one wire from one solenoid with one wire of the other solenoid,
then join the other wire of the solenoid with the remaining wire of the other solenoid so you have two terminals
instead of four. Connect any of the two solenoid terminals to the horn wire.
If you have a negative horn circuit, connect the remaining solenoid terminal to a constant 12-volt power
source.
If you have a positive horn circuit, connect the remaining solenoid terminal to ground.
