nosnow

I have an interesting issue that cropped up after reinstalling the dash and I can't see any issues so I hope someone might have run into this issue before.

89 S4 with digital dash. When I turn the car off the ABS light and Emergency Brake light (if ebrake is engaged) stay on until the digital cluster turns off or if I lock the car the lights turn off.

Any ideas? I have searched several times and combed over threads but have yet to find anything specific to this.

Ed Scherer

Assuming you've got your cluster refitted with LEDs, this is "normal" (although undesirable) behavior. It's even noted in a "Instrument Cluster Anomalies" sidebar in (currently on p. 30 of the current revision of) Converting Porsche 928 Interior Lighting to LEDs.

For some reason, there's a small amount of current that ordinarily (with incandescent bulbs) would go unnoticed (probably not even enough to warm the filament), but is enough to barely illuminate an LED.

It should be possible to solve this problem with some additional circuitry in the cluster, but I never pursued it further as this problem seemed like a minor issue.

nosnow

Thank you... I did do LEDs but didn't expect this. I guess I won't worry.