General Notes on Repairs on Vehicle Electrical System

General Notes on Repairs on Vehicle Electrical System

Special tools, testers and auxiliary items required

• Wiring Harness Repair Set VAS 1978/A (VAS 1978 B)


• Repairs to the wiring harnesses and connectors must only be performed using the Wiring harness repair set (VAS 1978 B).

• Observe the country-specific requirements.

• Use of the Wiring harness repair set (VAS 1978 B) is described in detail in the attached operating instructions.

• Repairs on open circuits and faulty connectors are also explained using examples.


Risk of injury.

• Pay attention to decals designating high voltage components. When performing repairs, residual voltage must be discharged.

• Some tools are supplied with a tool safety clip, which is slid over the tool points after using the tool, in order to protect other workers from injuries and tool points from damage.


• Observe the country-specific requirements.

• By disconnecting the battery ground (GND) wire, safe work on the vehicle electrical system is guaranteed. With the ignition switched off, disconnect the ground wire on the battery.

• Before starting a repair, the cause of the damage must be eliminated first, such as, sharp edges on chassis parts, faulty electrical consumers, corrosion, etc.

• If possible, do not loosen the ground (GND) straps from body (danger of corrosion).