Instrument Cluster lights intermittent

[simon84]

Hi,

on my 2004_09 X5 3.0d the instrument cluster lighting is intermittent.

Banging on the top of the panel usually brings it back on (when off) or off (when on).

All Internal LED lights are affected (also on the right side of the dash/airco controls etc, not only cluster itself).

I have already checked:

Instrument cluster itself:
Completely dismantled, checked electronics for signs of cracks/bad solder joints etc., used contact spray on all connections. Had the naked instrument cluster board connected and reproduced problem, banging on the dash itself , same behavior, even with KI hanging in the air completely decoupled from any "banging" effects

Did the same with the LCM module itself as well. When the problem occurs, a whirring can be heard in the LCM, as soon as I hit the dash and the lighting comes on, the LCM whirring goes away. Knocking/Tapping/Hitting the LCM itself or pulling on the wires does no change.

So it appears the LCM isnt at fault either.

Did same procedure with the board computer monitor /MKIV screen as well. Nothing to be found.

I had the impression when hitting the dash on the passenger side less force is required to make the lighting go on/off.

Any ideas ? Could it be that there is one LED which is short to ground intermittently ? How are they dimmed e.g. which component is doing the dimming? Dimming LED must somehow work by pulsing them, I dont think you can just dim LED with a resistor right ?

I checked the Dimmer in DIS and it shows 4V on lowest position and 0V on highest, so seems to be working as expected.

None of the modules (KI/LCM/Rain Sensor etc.) show any relevant errors when reading out with original BMW DIS system.

Does anyone know how the wiring runs under the dash? The fact that I can just hit the dash over and over again to make the lighting go on/off kind of makes me think its either a bad solder joint in another module I havent looked at yet, a bad wire/connection or a bad ground point somewhere....

Any input greatly appreciated

Cheers,

Simon

[simon84]

colleague told me to check splice X806 behind glove box (grey red wires)

will keep you posted

[simon84]

BIG WARNING. I ADVICE ALL E53 OWNERS TO CHECK THIS.

After I was done removing the glove box and the X806 checked out fine, i started to knock lightly against the ashtray and auto gear stick and seemed to be getting closer to the root cause.

I was already fumbling around in between and under the console with the gear knob removed and hand brake leather cover etc off, and luckily I was in a parking lot when I saw yellow sparks and smoke coming from below the hand brake. I turned off the car and removed the whole hand brake console panel.

As you can see the wiring loom which is part of the console itself was in constant contact with the metal brace and completely shredded the red-gray lighting wire as well as the brown ground wire and therefor shorted lighting to ground. Why no fuse blew, I dont know. But sure as hell the car was almost full of smoke.
The wiring loom seems to shifting back and forth when shifting park - Drive- reverse etc.

Planning to replace the wire and isolating and restraining it out of the way with cable ties tomorrow.

[TiAgX5]

Has the X every been to an electronics installation shop or are you first owner with only OE electronics?

The reason I ask is, when previous owners have electronics removed from vehicles B4 sale/trade in, the removal is usually rushed and without much care/concern for putting everything exactly where it was.

[simon84]

2nd owner, nothing was removed or added. Cabling looked stock... hopefully it was a mistake done on the assembly line and this doesnt look like this on all X's