anyone have a source - schematic diagrams for instrument cluster electronics E36

[enf1945]

328i
im having intemittent flashes of warning lights.
sometimes the engine temp dial goes to 0.
no problems with LED mileage display.

thanks

[shogun]

from 6211.0 instrument cluster, all details http://wedophones.com/Manuals/BMW/19...g%20Manual.pdf

[enf1945]

Thanks
i have that manual.

Was look for the schematic diagram for the instrument cluster itself

i guess that is an internal BMW document

[dcvaughn]

Thanks
i have that manual.

Was look for the schematic diagram for the instrument cluster itself

i guess that is an internal BMW document

Did you ever manage to track down an actual schematic for your cluster? I just pulled one out of my E36 that died a slow death until it caused all kinds of crazy side effects. One obvious problem is a smoked SMD resistor near a 12v pin on connector A. It's apparently part of a simple voltage divider that sets the reference voltage for door microswitches and the Alpine alarm/remote system...

Schematic would be a rarity! May sacrifice an all together different cluster to determine how to best strip the conformal coating from components and beige paint from the back of the PC board. If I get anywhere I'll drop the learnings back here.

[enf1945]

use a flat razor blade to take off the coating . be careful not to hit the component, or to cut yourself

[injuhneer]

I see this thread was bumped a few days ago. I am taking a pass at repairing the cluster for my son's 318. The cluster was opened and all obvious things cleaned or re-soldered.

While in there one thing looked wrong to me. There are a pair of transistors toward the top of the circuit board. Both have a heat sink attached. One is fine. The solder joints of the other look like the conformal coating has been hot or cooked a bit.

The cluster failure was abrupt. The gauges just stopped working. All the other functions (lights, SI, odometer, etc) are fine.

I am wondering if the transistor switches power to the gauges or some such. It would be nice to have a schematic to see what these transistors support in the cluster. I suppose they could be regulators. I haven't pulled the heat sink of to see the numbers for identification.

*** time passes ***

Heat sink is off. It is an ST BD437 low voltage transistor.

*** time passes ***

I changed out the transistor and verified the traces around it were ok. No improvement in the analog gauges but all the lights and checks seem to work now.


-MO