weird cluster behavior...

[Darth Elvis]

Hi there,
I have a 1994 318is with 170000km on it, and the cluster has taken to showing some strange intermittent behavior. all 3 brake system warning lights come on
along with both the high temp and low fuel lights, as well as the tach and fuel economy guages spike/jump around. this all happens at the same time.
This is not speed or load dependant, happens whether any other accessories are on
or off
The behavior only lasts for a second or two and does not affect the running of the vehicle. Problem does happen on a fairly frequent basis whether engine is hot or cold

Total weirdness, any ideas ? Acts like a loose connection or bad ground, but where would I start to look. I mean all the other lights in the cluster and the speedo are okay.
Thanks in advance for your help

 

[Pink_Floyd]

Problems like this are always difficult to diagnose. If I were you the first thing I would do is get in touch with someone with another e36 and try swapping the clusters. This will at least let you know if the problem is with the cluster or the car. Ideally it would just be a loose connection, but I doubt that as those connectors on the back are very secure. If your problem is with the cluster and you are good with electronics you can take it apart and look over the circuit board. If you are familiar with printed circuit boards then you should easily be able to find an area of corrosion that could cause random shorts.

If your problem is with the car itself then you should head over to www.unofficialbmw.com and get your Bentley manual out. Assuming you can't find any visible faults with the wiring harnesses you should begin checking the continuity of the wires from the cluster harness to the ECU harness. Find out which wires are bad and then either take your interior apart looking for the problem or run new wires. Unfortunately, if you are not comfortable with working with a multimeter and soldering you should probably take this into a qualified BMW shop.

Good luck!

 

[Kirby]

I had stumbled across a fix for this problem somewhere on the net. I tried finding it again for you but couldn't....

As I recall, the article said this problem can be caused by bad grounding on the PCB. Specifically, over time, the ground contacts for the various instruments oxidize. I think the soulution was to remove the cluster and clean each plug, socket, ground connection, etc.

FWIW, I have seen this problem on my '94 325i in the tail light assemblies. The ground traces were slightly dirty and the tail lights were intermittent. Cleaning the contacts solved the problem.

 

[epj3]

FWIW, I have seen this problem on my '94 325i in the tail light assemblies. The ground traces were slightly dirty and the tail lights were intermittent. Cleaning the contacts solved the problem.

My friends 94 has the same problem