LED Interior Lights
I was tired of being blinded
by the main interior lights, so I replaced them with LED-based equivalents.
- Provides some light in the car without killing
my night vision.
- No more of the too-bright lights when you open
the doors at night.
- The pattern of light from LEDs is more directional
and permits the light to be concentrated where desired with less stray
- They never need replacement.
- Matches the stock BMW-orange instrument lighting
perfectly. : )
You now can buy these preassembled from a number
of sources, but they are relatively expensive at about $15 - $20 each
versus about $4 in parts. Also, all of those that I've seen are not
as bright or as well patterned as the LED that I used.
NOTE: LEDs must be installed with correct
polarity; otherwise, either they simply won't work or you may ruin them.
See the following sites for more detailed
info regarding LEDs, how to build simple LED circuits, and sources for
The LED Museum - a good site for lots of
general information regarding LEDs - they "put the die back in
diode" ; )
How to build a simple LED circuit:
How to calculate proper resistance in a
simple circuit to correctly match LED power levels:
Hosfelt Electronics, Inc.:
The LED that I used is a ~605-620 nm orange
LED, 18,000-36,000 mcd, 10mm, Toshiba TLOH190P, Hosfelt part # 25-276
@ $ 3.49 each.
For pre-assembled interior lights much
better than those here, or other custom electronics involving LEDs,
see David's site at www.tunerdomes.com.
Excellent assembly quality and very good light output. Includes installation
LED Light Assembly
The picture below shows the components
used including: the LED above, a 250 Ohm resistor, a small piece of
circuit board sized to the length of the standard bulb, and the metal
end caps from a standard interior bulb.
LED Light Components
You can adjust the brightness and pattern
of light by using different components. The LED I used is the brightest
that I could find that matched the interior light color.
The 250 Ohm resistor is a little high for
The LEDs are 2 volt DC @ 60 mA.
Using the formulas above:
Assuming 14 volts (while the car is
running), the best match for a resistor would be 200 Ohm.
Assuming 12 volts, the best match would be 166 Ohm.
Anything between these values should be
OK. Less resistance will increase the brightness of the LED.
Assembly is very simple. The resistor is
wired in-line to the positive terminal of the LED. The end caps are
simply soldered to the wrapped end of the resistor at one end and the
negative lead (usually the shorter lead) of the LED at the other end.
The end result is a relatively bright,
directional light that's almost perfectly matched to the stock orange
I replaced only the center overhead light
above the rearview mirror and the two passenger lights at each side
in the rear. The light setup in the E39 is nice in that you have the
stock map lights to either side of the center light for brighter white
light when you want it in the front, the rear white reading lights are
independent and can be turned on separately if wanted, and the standard
white floor lighting provides indirect light down low.
The pictures below are attempts to show
It's difficult to capture the effect of
the lighting. The light from the LED tends to overwhelm the camera and
you can't really see how well it lights the interior. In any case, it
gives an idea of the brightness and color. I'd describe it as "night
light bright." I know that some others have added additional LEDs
to increase the amount of light.
The pattern of light from
the particular LED that I used is relatively narrow. You can aim the
beam somewhat by rotating the LED in the socket. I have the the light
concentrated on the center console in the front and at each of the seat
pads in the rear.
The lights all function as
normal, other than they fade a little faster than the normal lights
when the automatic cut-off turns them down.