VIAIR Heavy Duty OBA - Manual (Page 6)

USER MANUAL
HEAVY DUTY ONBOARD AIR SYSTEM
DASH PANEL GAUGE INSTALLATION
(USE CONTENTS OF PARTS PACKAGE #4)
Your VIAIR Heavy Duty Onboard Air System comes complete with a Dash Panel Gauge to monitor the pressure
of your 2.5 gallon VIAIR air tank. Additionally, the Dash Panel Gauge has an ON/OFF switch preinstalled that
will allow you to turn the system off by cutting power to the pressure switch with relay that you have already
installed. We recommend that you install a master ON/OFF switch to allow the system to be turned off any
time you anticipate leaving the vehicle parked for any length of time, and to avoid draining the vehicle’s battery
unnecessarily due to a slow air leak in your system. (see Figure 2)
IMPORTANT: Each Dash Panel Gauge has been tested and calibrated. The air inlet on this gauge has a factory
installed compression fitting. DO NOT attempt to tighten or loosen the body of this compression fitting.
Any adjustments will cause the gauge to malfunction and void warranty. The Dash Panel Gauge included in
this kit is rated for 150 PSI. Do not pressurize gauge over 150 PSI.
1. Select Mounting Location for Dash Panel Gauge:
Select a mounting location with a rigid mounting surface such as the bottom edge of the dashboard.
Use the gauge mounting panel as a template; mark off two mounting points to be drilled.
Carefully drill two 13/64” diameter holes as marked. Do not mount Dash Panel Gauge at this time.
2. Air Line Connection to Dash Panel Gauge:
Remove only the collar of the compression fitting from the back of the Dash Panel Gauge. Do not loosen of
tighten the body of the compression fitting, which is permanently affixed to the air inlet of the gauge. Insert air
line tubing through this collar, and then push air line tubing onto the barb of the compression fitting until the air
line completely covers the barb. Tighten collar onto the body of the compression fitting with a wrench.
3. Routing Air Line to Air Source:
Route the air line tubing on the Dash Panel Gauge to the air source. Do not cut air line yet. In some cases a
hole may need to be drilled to enable the air line to pass through to the air source. Make sure that the air line
tubing is protected from any sharp edges of the drilled hole using grommet strip supplied. Connect to the tank
using the 1/4” compression fitting supplied.
Installation Tips:
- When cutting air line tubing, always cut as squarely as possible. Use a hose cutter or razor blade.
- When routing air line tubing, always remember to avoid sharp edges, heat sources and tight bends.
(Air line must be routed at least 12 inches from exhaust systems & other heat sources.)
IMPORTANT - Drilling through firewall:
Always be sure of what is on the other side of the firewall before drilling.
Take care not to damage your vehicle’s electronic systems or components.
4. Wiring the ON/OFF Switch:
Attach one of the two remaining female terminal connectors to the wire that was routed from the pressure
switch trigger wire (Small Red Wire on pressure switch with relay) There are two male spade connectors on
the back of the ON/OFF switch. Connect this female terminal connector to one of the male spade connector
on the ON/OFF switch. Next, attach appropriate size ring terminal provided in the kit to the end of the wire
with the Inline Fuse. (The ring terminal should be about 12” from the inline fuse.) This wire is referred to as the
power wire. Temporarily position the ring terminal at the power source and route power wire to the dash panel
gauge, measure and cut to appropriate length. (If additional wire is necessary, use 16 AWG wire.) Attach the
remaining female terminal connector to end of power wire, and connect to male spade connector on the
ON/OFF switch. (Note: Do not connect gauge to power source at this time.)