4
5. Connect 3 wire mini connector power if required*.
Remove the jumper next to
the main connector if connecting to external power. This jumper is required for
OBD2 port power only
.
Connect separate
red
power wire, which exits the middle
of the 3 wire mini cable as shown in
figure 1
, to a switched 12v line or circuit in
the vehicle. These circuits are commonly known as “accessory” circuits because
they are only “hot” when the ignition is turned on. A recommended way of doing
this step is to use a product called an “
Add a Circuit
”, made by
Littelfuse
,
available at most car parts outlets. These kits, which sell for under $10, allow you
to easily use an existing circuit in the fuse block to power an add-on accessory
such as the
Interceptor
without the need to cut or splice any wires. The use of
this kit is highly recommended, as most of the problems with the gauge can be
traced to a poor selection of a 12v wire, or poor connection. If the gauge
randomly turns off and on while driving, 90% of the time it is a poor connection
to 12v or an improper circuit was tapped into, such as a signal wire to the
instrument panel.
*This power wire is not needed on most vehicles. Some early OBD2 GM and
Ford vehicles made from 1994-1998 may require this connection. If the
gauge is not turning on or off properly on these or any vehicle, you can force
it on and off at the proper time by removing the small 2-pin jumper on the
rear of the gauge and connecting the red wire to switched 12v as described
above.
Figure 2
