Lamp unit fogged or droplets forming.

Because of the housing cover with pressure compensation membrane, the lamp unit is a “closed system”.

This means that the lamp unit is protected against acid gases, dirt and exhaust gas.

However, moisture can still enter from two sources. Through absorption and desorption (the commonest cause) or through permeation.

Moisture is either absorbed by the plastic material and, when the light source is switched on, it is released from the plastic by desorption, or the moisture penetrates through the plastic materials of the headlamp from outside (permeation). This can lead to the formation of condensation on the lens of the headlamp.

Check housing cover of lamp unit for natural fogging or dew as per LI82.10-P-050151.

If a reduction in the degree of fogging is visible, the desiccant packs can be used once the condensation has completely evaporated.

1.       Remove lamp unit

2.     Cut open housing of lamp unit on inside of bar (picture 01), along the notch ( red dotted line in picture_03) using hot knife (WS82.00-P-0026B).

Make sure that the outer edge is not damaged during the cutting process.

Note: Risk of injury from burns to skin and eyes, risk of poisoning from inhaling vapors when working with plastics.

3.      Place desiccant pack in new service cover and bolt down (Figure 02)

4.      Stick existing transparent membrane onto surface provided

Note: The bonding surface must be clean and dry.

5.      Attach service cover with desiccant pack to headlamp

6.      If the headlamp housing has an additional 2nd membrane, this must be covered over with the masking tape.

Note: The bonding surface must be clean and dry.

7.       Reinstall lamp unit

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To ensure that the drying pack (absorption) acts effectively, the headlamp has to be air-sealed.

Observe or check the following points for this:

1. The seals on the central connector must all be present [Picture 5 (1)] and correctly fitted [Picture 5 (2)].

2. The new transparent diaphragm must be correctly bonded [Picture 6].

3. Check headlamp housing for any external damage.