Self Study Program 871003 – Wiring Harness Inspection & Repair

VAG SSP 871003. The purpose of this Self-Study Program is to provide essential background technical information about all aspects of the wiring harnesses used in Volkswagen vehicles. It describes why they are designed and built the way they are. It goes on to describe the repair fundamentals that, if respected, will maintain those high standards.

Wiring harnesses in Volkswagen vehicles have undergone a tremendous evolution over the past 30 years. Changing customer expectations, regulatory requirements, and advances in technology have resulted in broad proliferation of electrical and electronic components. Wiring harnesses have become much more complex. The number of terminals alone has increased from just over 200 in a typical 1966 model, to over 1,400 terminals in the latest models.

Cost has increased just as dramatically, from about 8% to more than 26% of the total manufacturing cost of the vehicle, making the wiring harness the single most expensive assembly in our cars. If that fact is difficult to accept, consider that it takes about 1-1/4 hours of direct labor to assemble an engine, but well over 5 hours are required to construct the wiring harness!

The difficulty associated with repairing the wiring harness has, unfortunately, kept pace. Smaller wires and terminals, carrying extremely low-level signals, with increasingly limited access, and more complicated, interlinked electronic control modules and sensors have all contributed to the “confusion factor.”

While we have continuously improved wiring harness design, layout and assembly processes, about half of all warranty repairs address electrical malfunctions, and roughly half of those, and one third of all tow-ins, are caused by problems associated with the wiring harness.

With that in mind, it is easy to see that the wiring harness can no longer be considered a simple, bound collection of wires and connectors. Every length of wire, every connection, every attachment, every twist and turn, is carefully engineered to suit the application and its environment. When repairs are necessary, they will be successful only when the quality of the repair and the components completely restores the wiring harness to its original integrity.

To assure quality repairs, Volkswagen has developed a simplified harness repair concept, and developed the VAS 1978 Wiring Harness Repair Kit. This kit provides everything that may be needed for proper, high-quality harness repairs. Within the framework of the new repair concept, any authorized repair can be carried out using the tools and hardware supplied in the kit. The harness must never be repaired by any other means.

This information is intended to assist you in completing critical wiring harness repairs properly, in evaluating the quality of those repairs, and in preventing recurrent problems by getting it fixed right the first time!


  • Introduction
  • Wiring Harness Design
  • Wiring Repairs
  • Crimped Terminals – Visual Checks
  • Seals – Visual Checks
  • Stabilant 22A
  • Wiring Harness Repair Kit VAS 1978
  • Summary
  • Acknowledgements
  • TeleTest

The self-study program is not a Workshop Manual!
Precise instructions for testing, adjustment and repair of various electrical and electronic systems can be found in the appropriate Service Information. Specific tools and procedures for proper wiring harness repair using the VAS 1978 Wiring Harness Repair
Kit can be found in the Instruction Manual provided with that kit.

Language: English
Format: PDF
Pages: 42

Self Study Program 871003 – Wiring Harness Inspection & Repair PDF free online