← Golf Volkswagen Golf repair manuals →
Autopapyrus · Volkswagen Golf (5th generation, Mk5)
https://autopapyrus.com/guides/volkswagen/golf/repairing-the-wiring-in-the-tailgate-boot/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Volkswagen Golf (5th generation, Mk5): Repairing the Wiring in the Tailgate Boot

On the Golf Mk5, the harness to the tailgate runs through a rubber boot on the hinge side. Constant flexing causes the conductors to break inside the insulation. This results in a rear window defogger that doesn't work, a rear wiper that doesn't work, no license plate lights, and a dead release button and lock. The repair consists of locating the break, soldering it and restoring the insulation, and routing the harness neatly.

Difficulty: Medium Time: 1.5-3 hours Steps: 12

Parts

3
№Part
01 Automotive repair wire, 0.5-0.75 mm², copper, stranded, insulated
02 Adhesive-lined heat-shrink butt connectors
03 Rubber boot (grommet) between body and tailgateif needed

Tools

10
  • Screwdriver set and plastic trim removal tools
  • sockets and ratchet
  • multimeter
  • soldering iron with solder and flux
  • adhesive-lined heat-shrink tubing
  • wire stripper
  • knife
  • zip ties
  • fabric harness tape
  • awl
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes and 36 more. See manuals →

Step by step

12 steps
  1. Determine which circuits are not working: rear window defogger, rear wiper, license plate lights, brake light in the tailgate, release button. This will tell you which wires in the harness are broken. The break is usually located at the flex point.
  2. Disconnect the negative battery terminal and wait a couple of minutes. If the car has a radio with an anti-theft code, find out the code beforehand.
  3. Open the tailgate. Use plastic trim removal tools to remove the inner trim panel of the tailgate without breaking the clips. Disconnect the connectors for the license plate lights, the lock, and the wiper.
  4. Find the boot near the left hinge. Carefully slide the rubber cover back from the body side and from the tailgate side. To do this, release it or pull it out of the openings by prying with an awl or screwdriver.
  5. Pull the harness out of the boot. If the wires don't come out, remove them gradually without yanking, and release the locking tabs on the connectors.
  6. Remove the outer braid or tape from the harness at the flex point. Inspect each wire: look for cracks in the insulation, darkened copper, and green corrosion. Check the continuity of each conductor with a multimeter in continuity mode, from the connector in the tailgate to the connector in the cabin.
  7. Do not solder all the repairs in the same place on the harness. Stagger the splices along the length of the harness by 2-3 cm so that no thick spot forms that would chafe inside the boot.
  8. Strip the wire ends by 5-7 mm. Slide adhesive-lined heat-shrink tubing onto each connection, solder the strands together or insert a section of wire of the required length, then shrink the tubing with a heat gun. Keep the wire colors consistent so you don't mix them up, in case the harness was repaired before.
  9. If the damage is severe, replace the entire length of wire from connector to connector. Make the replacement section with some extra length so the harness is not stretched when the tailgate opens.
  10. Reassemble the harness and wrap it with fabric tape. Apply a little silicone grease to the boot and pull the harness back through along its original path. Seat the boot in the grooves on the body and tailgate so that it does not fold or bend the wires too sharply.
  11. Plug in the connectors, reconnect the battery, and check the operation of the rear defogger, wiper, license plate lights, and release button. Open and close the tailgate several times, watching the harness.
  12. Reinstall the inner tailgate trim panel and secure the clips.

Common mistakes and warnings

  • The rear window defogger and wiper draw significant current: use wire of sufficient gauge and make the soldered joints properly, otherwise they will overheat
  • Do not replace damaged wire with a twisted splice
  • If the harness contains circuits connected to airbags or data buses, it is best to take the car to a repair shop if you lack experience