Installation Manual

14221-1850-4000, Rev. A
40
For thick-roof antenna mount AN-125001-004, using a ⅜-inch mounting hole requires
better access to the underside of the mounting location than if a ¾-inch hole is used.
This is because, in the case of a ⅜-inch hole, the antenna mount’s bushing assembly
must be inserted from the underside of the mounting surface.
When using a ¾-inch mounting hole to mount thick-roof antenna mount AN-125001-
004, the thickness of the mounting surface must be at least ⅛-inch (0.125-inch minimum
thickness). This is due to the thickness of the alignment ring used to center the bushing
assembly within the ¾-inch mounting hole.
7.2.1.3 Installation Procedure for Mounts AN-125001-002, -004, and -006
1. Select the antenna mounting location in accordance with the information presented in Section 1 of this
manual and in the Product Safety Manual. If necessary, contact the Technical Assistance Center for
assistance. See page 97 for contact information.
2. Verify no obstructions exist immediately below the respective mounting location on the underside of
the vehicle body, such as vehicle ribbing/body framing, a wiring harness, air bag equipment, etc. Also
verify there is a sufficient access path and clearance for the mount’s coax cable. If there is an obstruction
or insufficient clearance, select another nearby mounting location.
3. Measure and mark the center point of the selected antenna mounting location. Be sure to center the
mark from side-to-side of the vehicle.
4. Obtain a hole saw specifically designed for drilling NMO mounting holes of the required diameter.
(e.g., Antenex/Laird Technologies model HS34 or equivalent for a ¾-inch hole; Antenex/Laird
Technologies model HS38 or equivalent for a ⅜-inch hole).
5. If the vehicle’s headliner panel, carpet, seats, or other is below the mounting location, move or remove
the headliner panel, etc., as necessary to protect it. Alternately, apply a heat-resistant mask material
(such as a fiberglass mat or thin sheet metal with masked edges) as required to “catch” the metal
shavings and the metal plug (if any) produced by the hole saw. The plug (if any) may be relatively hot
if/when it drops out of the saw upon completion of the hole drilling process. ⅜-inch diameter hole saws
generally produce only shavings, not plugs.
Excessive use of the hole saw and/or failure to position the drill “square” with (i.e.,
at a 90-degree angle from) the vehicle mounting surface may result in damage to the
metal mounting surface, in the area immediately outside of the perimeter of the hole.
6. With the hole saw and a drill, drill a hole at the marked hole center point. Position the drill square to
(i.e., 90 degrees from) the vehicle mounting surface so paint immediately outside of the perimeter of
the hole is evenly removed.
7. Ensure the saw removed the paint immediately around the hole as the drilling operation completes. If
not, do so by reinserting the saw completely into the hole and spinning it as required. This allows proper
grounding via the mount’s lock nut on the top of the mounting surface. On the bottom of the mounting
surface, the “teeth” of the mount’s bushing assembly may not provide a good ground due to thick
vehicle undercoating, thick primer, oxidation/rust, etc.
For a ¾-inch hole, feed the unterminated end of the mount’s coax cable into the hole from the top
surface of the vehicle until the mount’s bushing assembly is in position to drop into the hole. The
bushing should be tilted at a slight angle and fed into the hole. The threaded shank of the mount’s
bushing assembly will not fall through a ¾-inch hole.
NOTE