Aftermarket Accessories - Installation Guidelines
90chevy15GMC NUMBER: 90-9-66
GROUP: 9 Accessories
DATE: June, 1990
CORPORATE
NUMBER: 038121
SUBJECT: INSTALLATION GUIDELINES FOR AFTERMARKET ACCESSORIES
MODELS: ALL TRUCKS, ALL MODEL YEARS
The popularity and variety of electronic aftermarket auto accessories is rapidly growing. Many of these devices require permanent connections to the electrical system of the vehicle. These installations are usually performed by the dealership, a specialty shop, or the customer.
Today's automotive electrical systems are very sophisticated. Improperly installed electrical accessories can interfere with the vehicles operation, performance, and in some circumstances cause damage to the vehicle which would not be covered under the General Motors New Vehicle Warranty. Possible problems to the vehicle are, but are not limited to: stalling, surging, poor performance, detonation, blown fuses, damaged wiring, cluster lighting changes, battery drains, alarm system failures, premature relay failures, poor radio reception, and radio speaker noises.
Many customers who encounter aftermarket accessory related problems may in error fault the original manufacturer of the vehicle as the cause of the problem. Therefore, in the interest of customer satisfaction, technicians should check for add-on (non OEM) electrical equipment as the first step in diagnosing electrical problems. If the vehicle is so equipped, disconnect the system to verify that these add-on "accessories" are not causing interference. Installation guidelines are listed below. These guidelines are intended to supplement, but not to be used in place of, the instructions supplied by the manufacturer. Instructions for add-on installations are the sole responsibility of the manufacturer of the radio, telephone, land mobile radio, or other accessory.
NOTE: Due to the vanety of the aftermarket accessories, consult the accessory manufacturer for addibonal details specific to their product. In general, there are three classes of aftermarket. equipment.
1. Devices that only mquire power and ground connections.
Avoid tying directly into the vehicle's wiring system.
Whenever possible use direct power and ground feeds from the battery or the accessory block stud on vehicles so equipped.
To eliminate voltage spikes do not tie into existing ground connections. Accessories that use low current can be grounded at the left door hinge pillar. Drill a 5.3 mm hole and use a 10 mm head screw P/N 11502704 with star washer P/N 11503663. (Parts are currently available through GMSPO.)
Install an in-line fuse holder on the power wire as close to the battery as possible. Only use fuses of the correct amperage as specified by the manufacturer of the add-on device. Twist the lengths of the power and ground wires together, as much as possible to reduce magnetic interference.
Route wires away from all existing harnesses. Pay particular attention to all ECM, ignition, and radio wiring.
If the device must be ignition operated, use the auxiliary ignition jack in the fuse box and install an in-line fuse. In some cases you may have to add a suppression filter (see Deloo Service Managers - Sound Guide).
2. Devices that require connections to vehicle systems or components Follow the above procedures for the power and ground connections.
When the accessory manufacturer's directions require the device be tapped into vehicle systems, such as speed sensor, door lock wiring, courtesy light circuits, etc., it is important to verify that the addition does not affect the intended function of the circuit or its related components, such as reduce signal strength, create a current draw through switches relays and connectors exceeding their ratings, or generate electromagnetic interference.
If a device is powered by tapping into an existing circuit, the power feed to the device must be of equal or numerically higher gauge size than the source circuit. This will help insure adequate failure mode protection.
Splices, taps, and other wiring alterations should be soldered and insulated, preferably with heat shrink tubing to prevent corrosion and resistance buildup. Avoid the use of quick-lock type splices.
3. Devices that transmit radio signals or magnetic waves. These include mobile telephones, 2-way business radios, C.B. radios, and Ham radios.
Figure No. 1:
The attached information has been developed and released previously by Delco Electronics and is included in the service edition of the
Delco Sound Service: For Managers and Technicians Pub-629. We are reprinting this information for your convenience (see Figure 1).
INSTALLATION GUIDELINE