Land Rover Discovery: Front and Rear Lamp Condensation

Some customers may complain of condensation/mist inside exterior lamps.

Condensation/mist is a natural phenomenon which can occur when there is a temperature difference between the inside and outside of the lamp unit.

This condensation is considered to be as a result of normal atmospheric conditions and replacing the light unit will not correct this symptom. With the introduction of clear lenses condensation is likely to be more noticeable but does not affect the performance of the lamp. Condensation will clear when the lights have been on for some length of time and in warmer ambient temperatures A lamp that exhibits condensation should be evaluated after a drying time where all the functions have been operated for a minimum of 30 minutes. If the condensation has started to clear during this time it indicates that the lamp sealing has NOT been breached and will eventually clear. The lamp must NOT be replaced

CAUTION:

Make sure that bulb covers are correctly installed and make sure that all breathers (tubes or membrane patches) are free from dirt and debris and are fitted correctly as these can all lead to the formation of condensation. If any of these are determined to be the cause of the condensation, measures should be taken to dry out the lamps and to make sure that the bulb covers are installed correctly

NOTES:

• The Owner's handbook clearly states that condensation may form on the inside of lamp lenses and is caused by atmospheric conditions. That it is not detrimental to lamp performance and will clear during normal usage
• Pools of water and high levels of condensation would indicate that the lamps sealing has been compromised. Check for damage and inspect the condition of caps and breathers
• Differing layout on the opposing sides of the vehicle can lead to different levels of condensation inside the lamps from side to side.

  As a result of this the rate at which condensation clears may also differ from side to side

• Photographic evidence of the condensation levels prior to and after drying time should be provided with every returned part. Failure to do so may result in the claim being rejected
• This information bulletin contains examples of normal condensation generated from atmospheric conditions. A thin mist can form on the interior of clear plastic lenses, this is not detrimental to the lamp's performance. This thin mist will eventually clear through normal use, exiting through the lamp's venting system

Condensation or moisture can be more noticeable during the months of spring and autumn when there is a likelihood of a higher moisture content in the air. It can occur when there is a temperature difference on either side of the lens surface. This can often be seen in the evening and morning sunshine or when cold water makes contact with a warm lamp lens. When a lamp is warmed unevenly by the sunshine the surface area in direct sunlight will be approximately 10ºC higher than the remainder of the lamp. When warm air circulates within the lamp and makes contact with the colder surfaces moisture can appear on the lens as water condenses out of the warmer air. Condensation may occur when washing a vehicle with cold water on a warm day or when the lamps are warm and vice versa. This is the same phenomena as with the formation of dew on the surface of a glass window pane The following illustration demonstrates the process:

1. Moisture formation
2. Cool surfaces
3. Air circulation (convection)
4. Warm surfaces

Shown below are examples of normal exterior lamp condensation. This would NOT be covered by warranty and the lamp(s) should not be replaced

In the photographs shown below, there are no visible streaks, drip marks or droplets in the condensation mist

In the photographs shown below, the condensation mist does not obstruct the view of the lamp interior

Shown below are examples of abnormal exterior lamp condensation that may be covered by warranty. Warranty may be accepted providing the lamp does not exhibit any visible signs of external damage

In the photographs shown below, note the large water droplets

In the photographs shown below, note the drip marks or streaks in the condensation

In the photograph shown below, note the standing water within the lamp

In the photograph shown below, note the thick mist covering the lens with water droplets

DTC INDEX

For a list of Diagnostic Trouble Codes (DTCs) that could be logged on this vehicle, please refer to Section 100-00. REFER to: Diagnostic Trouble Code Index - DTC: Central Junction Box (CJB) (100-00 General Information, Description and Operation).

Exterior Lighting Headlamp Adjustment

NOTES:

• The headlamp setting is 1.2 % below horizontal and parallel.
• Left illustration shown, Right is similar.

1. Align the headlamp beam setting equipment to one headlamp.
2. Switch the headlamps on and to dipped beam.

NOTE:

NAS vehicles have vertical adjustment only.

• Adjust the headlamps with an Allen Key.
• Rotate the adjuster 'A' for horizontal alignment.
• Rotate the adjuster 'B' for vertical alignment.

To adjust the second headlamp, repeat the above procedure.

HeadlampsExterior Lighting / Description and Operation

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