Computers and Control Systems: Service Precautions

AFTERMARKET (ADD-ON) ELECTRICAL AND VACUUM EQUIPMENT
Aftermarket (Add-on) Electrical and Vacuum Equipment is defined as any equipment installed on a vehicle after leaving the factory where the vehicle was originally assembled that connects, in any way, to the vehicles electrical or vacuum systems. No allowances have been made in the design of this vehicle for this type of equipment. Therefore, addition of aftermarket equipment must be done with the utmost care for the vehicle.

NOTICE: No add-on vacuum equipment should be added to this vehicle.

NOTICE: Add-on electrical equipment must only be connected to the vehicles electrical system at the battery (power and ground). Add-on electrical equipment must not be connected to the vehicle electrical system any place but at the battery.

Add-on electrical equipment, even when installed to these strict guidelines, may still cause the powertrain system to malfunction. Therefore, the first step in diagnosing any powertrain problem is to eliminate any and all aftermarket electrical equipment from the vehicle. Once this is done, if the problem still exists, it may be diagnosed in the normal manner.