Odometer fails after "electrical event;" speedo soldiers on

[RDM]

All,

As I was accelerating onto the highway last Monday, my car experienced some sort of electrical event. The car became unwilling to rev. The dash lights (fused, thanks, Pelican!) went out. The clock stopped working. The odometer stopped working. All the gauges still worked, though.

I don't know what happened to cause the event, but noodling with the oxygen sensor relay resolved the revving problem. A new fuse resolved the lighting and clock problem.

But the odometer is still dead. That it went out at the same time as all the rest points toward an electrical problem. Is there a way for these to fail electrically rather than the typical failed nylon gear?

Anyone have a line on a speedo shop in Germany should it come to that?

Thanks.

[GeorgeK]

Electric surge? How's the voltage regulator?

[RDM]

The voltage regulator is one of the solid state external ones, new about 18 months ago.

[db_cooper]

Maybe the ground strap between the battery and the chassis is due for a change..or the ground strap between the transmission and the chassis under the car. That would explain your electrical brown out. Or..could be your ignition switch..

The Odometer is driven by the motor that drives the speedo...that is likely coincidental to your brown out, you have a bad gear in the Odometer..it just happens

[ben parrish]

Yup..bad gear

[db_cooper]

Try the Porsche Owners Club Germany...if Google translate is working..reach out and see who may be nearby that can make the repair..the odometer is a very common problem

Porsche Owners Club Germany - DER Club fΓΌr Fahrer und Freunde des luftgekΓΌhlten Porsche 911

[RDM]

Originally Posted by db_cooper

Maybe the ground strap between the battery and the chassis is due for a change..or the ground strap between the transmission and the chassis under the car. That would explain your electrical brown out. Or..could be your ignition switch..

The Odometer is driven by the motor that drives the speedo...that is likely coincidental to your brown out, you have a bad gear in the Odometer..it just happens

Both ground straps are new in the last 3 months.

My ignorance is showing- how does the ignition switch cause electrical spikes?