Renault Koleos Service Repair Manual: Heated rear screen: Repair

The screen printed heated grid on the inner face of the window may have an accidental cut, making the affected part of the circuit useless.

• Determine the exact location of the cut using a voltmeter.

  Faults such as these can be repaired by using the heated rear screen varnish available at the. Magasin Pièce de Rechange

I - DETERMINING THE EXACT LOCATION OF THE CUT USING A VOLTMETER

• Switch on the ignition.
• Press the heated rear screen switch.

1 - Detection between lines B and A

• Connect the + wire of the voltmeter to the + feed terminal of the rear screen.
• Put the - wire of the voltmeter on a filament at the - terminal side of the rear screen (line A); the voltage obtained should be roughly equal to that of the battery.
• Move the - wire towards line A (see arrow): the voltage gradually drops.

• A sudden voltage drop indicates that the filament is cut at that point (repeat this operation for each filament).

2 - Detection between lines C and A

• Connect the - wire of the voltmeter to the - terminal of the rear screen.
• Put the + wire of the voltmeter on the filament at the + terminal end of the rear screen (line C); the voltage obtained should be roughly equal to battery voltage.
• Move the + wire towards line A (see arrow): the voltage gradually drops.

• A sudden voltage drop indicates that the filament is cut at that point (repeat this operation for each filament).

II - REPAIRING THE FILAMENT

• Clean the section to be repaired to remove all dust or grease, preferably using alcohol or a glass cleaner, and wipe with a clean, dry cloth.
• To ensure that the new line is straight, before varnishing, apply adhesive tape to either side of the section to be repaired, leaving the conducting line exposed.
• Before using the varnish, shake the bottle to prevent the silver particles settling at the bottom.

Repair

• Carry out the repair using a small brush, applying a sufficiently thick layer. If applying successive coats, allow sufficient drying time between each coat and do not repeat the operation more than three times.
• Any varnish that runs over can be removed using a knife, but only after several hours of drying.

• The adhesive tape used as a guide must not be removed until approximately one hour after application.

  The tape must be pulled off perpendicularly to the resistance, in the direction of the arrow. Varnish applied at an ambient temperature of 20ºC will be completely dry in three hours. At lower temperatures, the drying time is slightly longer.