No interior lights? - Solved, DIY

[S1L1SC]

None of the front interior lights work - but rear reading lights will turn on.
I have checked bulbs, I have one of the front ones burned out, not sure if that would cause all of the front interior lights to not work?

[shogun]

Is the switch set to permanently off? One switch has 3 steps http://750il.bmw7.hu/owners_manual/images/page_036.jpg

[DV8OR]

If the center light in the light panel by the sun roof control most of the interior light with the door. Mine goes out once it a blue moon, if I flick it all the interior light come on with the door.

[S1L1SC]

Nope, switch is set correctly - no lights with door open or closed. Front reading lights don't come on either - maybe a fuse or broken wire?

[shogun]

Ge your multimeter out and check it. Sometimes the switch of the interior light get's damaged. You have to remove it, disassemble and check it. At the same time you can also check if the wire connector is attached to the interior light.
Fuses you can check, they are all listed and shown in the wiring diagrams http://shark.armchair.mb.ca/~dave/BMW/e32/

[E32FAN]

Please see Page 6330-02 and -03 of the ETM.

If you pry down the dome light switch assembly and short the RED/WHT wire to the BRN wire, you will see all the lights burn brightly! If not, then F33 is suspect.

The Dome Light Switch (E34) has a high failure rate because it is not adequate to swith its lamp loads. You can replace it, or just short BRN/RED and YEL/BLU wires together, and then your interior lights will be automatically controlled by the door switches, etc. This works quite well, in practice.

[Auzeras]

Yeah check your fuses, I had a tiny crack in the fuse under the seat that caused intermittent light failure. Clean the switch, if that's the issue you can either modify as E32Fan suggests OR put an LED light in which will lower the current draw.

My issue with LED's from stores is they are too cold, I make my own with quite warm yellow SMD bulbs, interior lights I make with 3x rows of 3x LED's and a single resistor. Plenty bright and won't drain the battery if left on all day :D I always stock a variety of LED components so easy for me, might be easier to live with the issue or just modify the switch, especially if you can't be bothered making things like this & have to order stuff in.

[S1L1SC]

Which wires do I short?

I have: Brown, red, gray and orange/brown to choose from:
http://www.lauterwasser.net/E32/Dome-Light.jpg

[E32FAN]

If you solder a wire between pins 3 and 4 (GRY & BRN/ORG) in the lamp assembly, this is the same as permanently selecting the "AUTOMATIC" switch setting, so the RM relay module will control the interior lights automatically. Leave the switch set at OFF or AUTOMATIC. (If you choose MANUAL then the reading lights will drain your battery for sure!)

shogun may help us to understand why the wire that is supposed to be YEL/BLU is instead GRY. In Japan, somebody would surely fall on his sword!

[S1L1SC]

Some success - fuse 30 was dirty - pulled it and cleaned it, now the lights come on - but only with pins 3 & 4 shorted. The map lights do not work at all, manual switches do not work.
With the bypass removed, none of the light come on. Bad switches on the light assembly, or maybe a broken wire? Looks like the little plastic legs on the rocker switches might wear out over time and not make contact?

- - - Updated - - -

So here is the fix:
(EDIT: read potential failure cause #3 below first before you start prying the assembly apart...)

Remove the entire assembly from the car. (it disconnects from the harness underneath the panel that covers the sunroof motor).
remove the clear lens panel from the front of the assembly. There are four tension clips on one side (remove from inside the assembly with a flat head screwdriver - be very careful, do not break them off)

http://www.lauterwasser.net/E32/CoverPanel-01.jpg

And two tension clips on the other side:
http://www.lauterwasser.net/E32/CoverPanel-02.jpg

The lens panel should now pull free and you should have access to the rocker switches:

http://www.lauterwasser.net/E32/CoverPanel-03.jpg

Again, very carefully so you don't break anything, pry the rocker switches loose - they are held in place on both side by a short little pin. They will simply pop back down into place with a little pressure when you are ready to re-install them:

http://www.lauterwasser.net/E32/CoverPanel-04.jpg

(Sorry about the fuzzy picture, I really did not want to tempt fate and pry everything back apart once I got done and looked at the pictures).
The switch works by compressing two pieces of metal together in order to establish a connection.
http://www.lauterwasser.net/E32/CoverPanel-05.jpg

Cause of failure:
1) The bottom piece get pushed down over use and the top piece can no longer reach it.
2) The little black plastic foot on the rocker switch that does the pushing gets worn down and now is too short - it no longer makes a connection when you flip the switch.
3) the little hump that the switch rides on get worn down and the switch no longer "clicks" in place - that can be fixed with some pressure from a flat head screw driver. Apply pressure from inside the assembly - no need to remove rocker switches for this - It miight be worth trying this before you remove the lens cover and rocker switches as it is a lot less labor intensive.

The Fix:
Pry the bottom metal piece upward so that the connection get re-established when the switch is flipped.
Placing something underneath it to prevent it from getting bent back down might be a good idea

OR - permanently connect the two pieces together in your preferred setting - you loose the use of the switch, but you don't have to worry about having to come back and fix it in the future.

Re-assembly is the reverse of removal.

[Derek K]

Great write up and pictures (I know how hard it is to get focus with digital cameras). Thanx