C 2500 Truck 2WD V8-5.7L VIN R (1997)
Antenna location is a major factor in these effects.
b.
The antenna should be a permanent-mount type, located in the center of the roof or center of the rear deck lid.
If a magnet-mount antenna is used, care should be taken to mount the antenna in the same location as a permanent-mount type.
If a disguise-mount antenna is used, great care should be taken to shield (using copper tape, etc.) any tuning network from vehicle
electronics and wiring, or mount the tuning network in an area completely clear (6 inches or 15 cm away) of vehicle electronics and wiring.
c.
Standard metal mount antennas may be mounted on a vehicle with non-metallic body panels by two methods:
1.
Mount the antenna near a metal frame section and bond the antenna mount to the frame with a short metal strap, which will provide the ground
plane connection.
2.
Some antenna manufacturers may offer "Ground Plane Kits" that consist of self adhesive metal foil that may be attached to the body panel to
provide a ground plane connection.
d.
Glass Mount Antennas
Glass mounted antennas should be kept as high as possible in the center of the rear window or windshield, between rear window defrost
"grid lines", if present.
Some vehicles use glass that contains a thin metallic layer for defrosting, or to control solar gain. GLASS MOUNT ANTENNAS WILL
NOT FUNCTION WHEN MOUNTED ON THIS TYPE OF GLASS.
3. Antenna Cable Routing
a.
Always use high quality coax cable (95% shield coverage minimum), located away (at least 6 inches or 15 cm) from ECM's, PCM's and
other electronic modules.
b.
Care should be taken to maintain as great a distance as possible between any vehicle wiring and coax cable.
4. Antenna Tuning
It is important that the antenna be tuned properly and that reflected power be kept to less than 10% (VSWR less than 2:1) at all operating
frequencies.
Important:
High VSWR has been shown to contribute/cause interference problems with vehicle systems.
5. Radio Wiring and Power Lead Connection Locations
a.
Methods to connect radio power on General Motors vehicles is dependent on the vehicle model (See Figure 1 - One Piece Transceiver
Installation or Figure 2 - Trunk Mount Transceiver Installation as needed).
Do not connect the negative power lead to any under-dash termination point.
One of the following four methods is suggested:
1.
Connect the positive and negative power leads directly to the battery terminals.
GM approved methods of connecting auxiliary wiring include the adapter package illustrated in Figure 4 - Power Cable Battery Connections.
Important:
It is recommended that a fuse be placed in the transceiver negative power lead.
This is to prevent possible transceiver damage in the event the battery to engine block ground lead is inadvertently disconnected.
2.
Connect the positive lead to the auxiliary power terminal (usually identified by a red plastic cover in the underhood area).
Connect the negative lead directly to the negative battery terminal.
Important:
See above important statement regarding fusing the negative power lead.
3.
Connect the positive lead to the auxiliary power terminal (usually identified by a red plastic cover in the underhood area).
