Td5 D2 electrics - Internal Courtesy lights

There are three factory-fitted interior lights. Each housing offers manual control over the light's operation, and the BCU is programmed to operate them all on demand and to fade them down on demand as well. There is also a glove box light that only works when the sidelights are on. Some models also have illuminated vanity mirrors on the sun-visors. All of the bulbs are the traditional 'festoon' type and can vary between 5 and 10 watt. If all the lamps are operating that can add up to a 40watt draw. 

Swapping out the Tungsten festoons for equivalent LED's is an easy upgrade. They are cheap, readily available and come in a range of styles and colours.

The main advantages of LED over Tungsten is reduced power consumption and extended lifespan. It is often claimed that LEDs use less then a tenth of the power to produce the same level of illumination. They also 'run' a lot cooler in terms of temperature.  

All the light fittings use a 36mm long Festoon bulb. They are available in a range of lengths and there are lots of different arrays of LEDs to select from.

I bought the above LED boards cheaply from the Internet. I choose to get both 'white' and 'red' LEDs and also bought 16 and 8 segment LED boards as an experiment. One of the 16 LED boards is shown above. 

Swapping them over is simple enough, but it must be noted that LED boards are polarity sensitive and may not work if connected the wrong way. It is easy to check this by simply swapping contacts in the light fitting. There may well be '+' or '-' marked on the reverse of the board as a guide. LEDs don't respond to a continuity test like a normal filament bulb would, so the only real way to test them is to supply them with current. 

Front Courtesy Light 

This is mounted on the overhead console above the driver, but the same fitting is also used in the rear cargo space.

Looking at the internal layout of the fitting, I got to thinking that there was a lot of room in there for an extra light fitting...

I made the extra terminal plates by cutting some spare metal strip to shape and fixing them to the existing terminals in the light fitting with some small nuts and bolts.

I quickly learnt that if I really wanted to cram more LEDs in there then the easier option was to buy bigger LED boards in the first place!




Rear Passenger Courtesy Light.

This is a physically smaller fitting and it uses a single latching button to manually over-ride the automatic function. The same size bulbs are used and the light fitting is mounted on the overhead panel between the small cargo nets.

Depending on the vehicle trim level, this panel also mounts the rear sunroof control whether it is manual or electric and also the rear air conditioning control. 

Hx originally had the manual-wind sunroof and when it was swapped over to electric, the 'electric' version of the panel as shown above was needed. The panel was sourced from a breakers yard and it arrived c/w the courtesy lamp attached. It was soon realised that the panel could be modified by opening out the blanked-off air-conditioner mounting and installing the 'spare' courtesy lamp in there. 

The additional lamp unit is fitted with a red LED board and it is wired independent of the BCU so that it will operate manually via the attached latching push-button.


Further Thoughts.

There is a lot of scope here for experimenting with different lighting effects that can appeal to individual taste. I know that changing over to the LEDs got me thinking about other options for internal lights...

Those thoughts would eventually lead to me installing some foot-well lights both front and back, some front door 'puddle' lamps and some rear passenger door 'marker' lamps. And as if that wasn't enough, some online research revealed LR installed a different front courtesy lamp unit into 'final-build' Discovery's.

Each of these options now has its own post...