1998 5.7L Tachometer Not Reading Correctly

[mowinkid37]

I have a 1998 5.7L 2bbl w/ thunderbolt V and just recently the tachometer has not been reading correctly. its consistantly ~1500 RPMs off where it should be. the gauge does activate every time but isnt correct. is this more likely the gauge or the electrical signal to the gauge. do these gauges act funny when the battery is low?

Thanks!

 

[dubs283]

if the tach is original it's 23 years old, probably a bit worn

have you tried lightly smacking it? usually the trick to get a tach to "normalize"

a "low" battery can cause many issues