Tachometer Problem

[bwb3]

My '92 with 76K miles idles, accelerates and shifts normally. However, the tachometer now shows about 300 RPM idle, shifts with normal acceleration at 2,000 RPM, 3,000 RPM with brisk acceleration. Car cruises at 70 MPH at 1,500 RPM. It works smoothly so I don't think it is sticking, possibly just not getting or processing the electrical signal.

Is the problem pinpointed to the tachometer guage, and not a sending unit, if the engine is operating normally?

Can the tachometer be removed from the guage cluster and replaced (swapped with a used unit)?

I had similar problems with my Volvo tach but it affected the transmission shifting. My mechanic sent the tach off to be rebuilt. A place in VA, I believe.

Thanks for any insight.
Gene