Well, I climbed under the car this morning, found the cable going from the frame to the transmission, removed the bolt and cleaned it to shinny new (also the cable end) and put it back in. Did mostly the same to the transmission end but didn't remove the entire bolt.

Result when I started the car? No change in tachometer operation. (insert sad face here.)

Oh well, If you or anyone else has a suggestion, I would be glad to hear it as I have no idea where to go next.

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