Accessories - Radio Telephone/Mobile Radio Precautions
Bulletin: 85-9-13Date: May 1985
Ref.No.: 85-238-9
SUBJECT: RADIO TELEPHONE/MOBILE RADIO INSTALLATION GUIDELINES
MODELS AFFECTED: ALL WITH RADIO TELEPHONE/MOBILE RADIO
Included in this Service Bulletin is the Radio Telephone/Mobile Radio Installation Guidelines and Problem Information Sheet. This information should be used by dealer personnel in reviewing the mobile users concerns if a vehicle-transceiver malfunction should occur.
Radio Telephone/Mobile Radio Installation Guidelines
Certain radio telephones or land mobile radios or the way in which they are installed may adversely affect the vehicle operations such as the performance of the engine and driver information, entertainment and electrical charging systems. Expenses incurred to protect the vehicle systems from any adverse effect of any such installation are not the responsibility of General Motors Corporation. The following are general guidelines for installing a radio telephone or land mobile radio in General Motors vehicles. These guidelines are intended to supplement, but not to be used in place of, detailed instructions for such installations which are the sole responsibility of the manufacturer of the involved radio telephone or land mobile radio.
Side Terminal Adaptor Package:
Auxilliary Electrical
Equipment
GM Recommended Installation
AC-Delco Side Terminal Adaptor Package 1846855, when combined with the longer battery bolt (P/N 7803) and spacer (P/N 7804) will provide the simple, tight, corrosion resistant connection illustrated.
TRANSCEIVER INSTALLATIONS:
INSTALLATION GUIDELINE
(refer to the enclosed figures during installation)
1. Transmitter Location
A. Locate transceiver for remote radios on driver's side of trunk as near to the vehicle body side as possible.
B. One piece transceivers should be mounted under dash or on transmission hump where they will not interfere with vehicle controls or passenger movement.
2. Antenna Installation
A. The antenna should be a permanent mount type located in the center of the roof or center of the rear deck lid. Glass mounted antennas should be kept as high as possible in the center of the rear window or windshield. If a magnetic mount antenna must be 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 tuning network from vehicle electronics and wiring or mount tuning network in an area completely clear of vehicle electronics and wiring.
B. Each vehicle model and body style reacts to radio frequency energy differently. When dealing with an unfamiliar vehicle, it is suggested that a magnetic mount antenna be used to check the proposed antenna location for unwanted effects on the vehicle. Antenna location is a major factor in these effects.
3. Antenna Cable Routing
A. Always use a high quality feedline (at least 98% shield coverage) routed away from the ecm and other electronics modules.
B. Care should be taken to avoid routing feedline with any vehicle wiring.
4. Antenna Tuning
A. It is important that the antenna be tuned properly and reflected power be kept to a minimum. (vswr 2:1)
5. Radio Wiring and Connection Locations
A. Transceiver battery and ground:
These connections should be made directly to the battery itself including the ground or to the jump start block on vehicles so equipped. The transceiver power feeds should be #10 awg wire or larger, twisted if possible. Again, the ground wire should not be attached to the body at any point. In-line fuses should be located as near as practical to the battery for ignition switch control of one piece transceivers. note:
It is recommended that a fuse be placed in the transceiver ground lead to prevent possible damage to the transceiver, in the event the battery to engine-block ground is inadvertently disconnected.
B. Handset or control unit battery and ground:
it is preferable that the handset or control unit battery lead be
connected directly to the battery. Any ground lead from a handset or control unit must return to battery negative. If it is necessary that the transceiver power be controlled by the ignition switch, then handset or control unit battery lead may be connected to the ignition 3 circuit at a terminal so labeled on the vehicle fuse block. A sketch of the fuse block is located in the owners manual. For ONE PIECE TRANSCEIVERS, where ignition switch control is necessary, a 12v power contactor must be installed in the transceiver battery lead. The contactor should be located at the vehicle battery with the coil of the contactor driven from the ignition three circuit at the fuse block. The coil of the contactor must return to battery negative.
C. Connections for multiple transceivers and receivers:
if multiple transceivers or receivers are to be installed in the vehicle, power feeds (+12v and ground) to the trunk or under dash should be terminated in covered insulated buss bars. All transceivers or receivers may then have their power feeds connected to the buss bars. This makes a neater installation and reduces the number of wires running to vehicle underhood.
6. Wire Routing
A. The power leads should be brought through a grommet on the driver's side firewall. For trunk mounted transceivers, the cables should continue on along the driver's side door sills, under the rear seat, and into the trunk through the rear bulkhead. If the battery is located on the passenger side, battery leads should cross the vehicle in front of the engine. All attempts should be made to maintain as much distance as possible between radio power leads and vehicle electronic modules and wiring.
B. For police vehicles, radio power leads should be routed in the conduit provided with the option package.
7. Troubleshooting
A. Should vehicle problems develop following installation, the source of the problem should be determined prior to further operation of the vehicle.
B. Possible causes of vehicle problems include:
1. Power feeds connected to points other than the battery.
2. Antenna location.
3. Transceiver wiring located too close to vehicle electronic modules or wiring.
4. Poor shielding or connectors on antenna feedline.
8. Contact and Feedback
A. GM vehicles have been designed and extensively tested for immunity to known sources of RF energy. However, it is impossible to test for every source, installation, or combination of sources. If a persistent condition is encountered, contact Delco Electronics Division on:
Dial Delco Indiana
1-800-428-0501 1-800-382-0531
VEHICLE-TRANSCEIVER PROBLEM INFORMATION SHEET
NAME_________________________________________________________ PHONE________________
AFFILIATION__________________________________________________________________________________
MAILING ADDRESS______________________________________________________________________________
STATE_______________________________________________ ZIP CODE____________________
DATE__________________ REFERRED BY_______________________________________
..............................................................................................................
VEHICLE MOBILE TRANSCEIVER
MAKE____________________________ MAKE_____________________________
MODEL___________________________ MODEL____________________________
VIN_____________________________ POWER____________________________
LOCATION OF EQUIPMENT. FREQ.______________________________
(SEE OVER) ANTENNA TYPE_______________________
..........................................................................................................................................
DESCRIBE PROBLEM:
MAIL TO:
ELECTROMAGNETIC COMPATIBILITY DEPT - MR BLDG 40
GENERAL MOTORS PROVING GROUND MILFORD, MICHIGAN 48042-2001
INSTALLATION LOCATION WORKSHEET:
PLEASE NOTE LOCATIONS OF THE TRANSCEIVER, CONTROL HEAD (IF ANY), ANTENNA, HARNESS ROUTING, PLUS BATTERY CONNECTION AND GROUND CONNECTION.