Power and Ground Distribution: Service and Repair: Overview

The wiring of the SAAB 900 consists of individual color-coded and insulated cables bound together into cable harnesses which run from the car's fuse boxes.
The fuse boxes contain fuses and relays and are situated in the engine bay and the dashboard. The wiring is split up into different logical sections, such as the front wiring, engine wiring, instrument wiring, rear wiring, door wiring, roof wiring and tailgate wiring.
This is so that only a small wiring harness need be replaced if one or more cables develop faults or are damaged.
All cable connections consist of solderless terminals. Most of the connections in the engine bay are of moisture-proof type.
In the event of electrical trouble occurring, the connectors and terminals concerned should be examined to make sure that the fault is not due to poor contact causing an unnecessary voltage drop. Should one or more fuses blow frequently, or if damaged insulation is suspected, an insulation test should be carried out on the wiring.


NOTE: Remember that a short-circuit in the wiring between the power supply source and the fuse will not cause the fuse to blow.


When fitting new cables, always make sure that the cross- section area of the conductors is suitable for the current that will be carried and that the cable is suitably protected by grommets where it passes through sheet metal and where it held by clips.
Wiring diagrams and the operation of the different systems are described in the relevant systems.


NOTE: Follow the fitting instructions when installing extra equipment. Failure to do so may result in malfunctioning of the electronic equipment and control modules, or may even cause irreparable damage.