Tachometer misreading big time

["Bruce Woodward" <brucewoodward@kconline.com>]

any ideas why my tachometer reads twice as much as it should?  a pleasant
700rpm idle reads 1500, I'm redlining at approx 4000 rpm.

Car had been halfa**ed converted or inadvertently converted to negative
ground, and after putting motor back in after cleanup and painting of engine
compartment as well as welding in new floors and spring mount area, I hooked
it up as postive earth and was pleasantly surprised to find tachometer
working, but with above mentioned problem.

your thoughts are greatly appreciated.

Great screensaver, Amy!  Taking it to my real estate brokerage for the
public to enjoy it also.

bruce@woodward-realty.com