W140 TAchometer GLitch

[casey10]

This is my weekly post! I am addressing and repairing each item one at a time. I've owned my 92 300sd for five months and driven it over 10000 miles. It is very dependable. SInce owning it, it has had a glitch in the tach where it will drop to zero for a few seconds and return to the proper RPM. Does not effect the engine operation, and is not effected by bumps in the road. It just randomly cuts out and drops to zero. The previous owner had two wiring harnesses replaced at the dealer to correct this, with no improvement. ANy ideas?
Thanks!

[rdanz]

The instrument cluster in these cars have had there share of problems,The next time the tach drops put you hand on the cluster and try to move it in and out.

[lyonstexas]

Had the same problem with my 92 300se. Sent the whole cluster to George Murphy, the National Technical Dierctor for MB, who has a private business repairing electronic components for a variety of MB models. Haven't had a problem since. Think it was around $300.00 but George will quote you when he has a chance to inspect it. Turnaround was 7-10 days if I remember correctly. It's been a couple of years. Check the STAR for his contact info.

Tim