User Manual

Guardian Field Support Manual – Section 2
50
To Find a Ground Source (Black Wire):
All vehicles have a metal chassis, which is
grounded. Most metal bodies around the fuse
box are a good ground source; however, you
must check the grounding during installation.
Ensure the ground connection is free of grease,
paint, plastic, corrosion, dirt, dust and is
secure.
One way to find a good ground is by switching
your Multimeter to the symbol, this is an
audible alert for when the multimeter probes
touch together through a contact.
Test the audible tone by touching the probes
together. Now, when you touch a known
ground source to the spot you want to mount
the ground wire to, you will hear an audible
tone. This indicates that the site is grounded.
The tone should be a long beep until the probe
is removed.
If the audio is interupted you may have a bad
spot or grease, dirt, or corrosion may be in the
way.
Touch one probe to known ground source like
the outter ring of the cigarette light socket
Touch the other probe to your planned ground
point, to ensure you have a good ground
connection
Note: If the system is not grounded correctly it may appear functional but lose power or reboot
when vibration occurs.