TERION UM20-100111B, Installation Manual, Page: 31 / 78

9. Clean the best ground point, identified by performing the measurements in
Section 4.2, so that the ground strap terminal will contact clan, paint-free
metal. Cut the braided ground strap to length and crimp the correct ring
terminal to the strap. Remove the bolt found in Section 4.2. Place the
ground bolt through a star washer, followed by the ground strap terminal,
and then through another star washer. Put the assembly through the bolt
hole, and then add a flat washer and a self-locking nut. Apply conductive
(copper-colored) grease and tighten the nut.
10. Verify the resistance from the antenna mount to the frame rail is less than 1 ohm.
Note: For this measurement, make sure the power is not plugged
into the ITU, and the coax cable is not connected to the antenna.
The truck must be off, and everything using the truck's batteries
must be off (e.g., turn off lights, keep the doors closed so the cab
light does not come on, turn off any appliances like refrigerators,
etc.).
11. Place a bead of dielectric silicone grease (clear grease) around the base of the antenna
stud mount where the upper portion of the coaxial cable connector will be connected.
Leave the last three to four threads clean. This will prevent moisture from getting
into the assembly and still maintain good metal-to-metal contact with at least three
threads.
Note: The easiest way to determine where the upper part of the
connector will be connected is to connect it and examine how high
on the stud mount the connector sits. Don't use too much silicone
grease.
12. Attach the FM/DHF coaxial cable to the antenna stud mount and tighten the
connection.
13. Determine the best point for the FM/DHF and GPS antenna cables to enter the truck
cab. It should, preferably, be under the cab. Look for an existing hole that may have
a plug in it. Use the existing hole if there is one. Otherwise, you will have to drill
through the cab skin. Start the hole with a center punch, drill a 1/8" pilot hole, and
then drill a 3/4" hole. Use a de-burring tool to smooth the edges of the hole.
4-15
Mobile Messaging System Installation Manual June 15, 2001
UM20-100111B Terion, Inc.