My tach has been doing the exact same thing for months now but my '93 Pathfinder runs great. I suspect it's a short somewhere in the wiring harness or a bad ground connection? Sometime when I adjust the electric mirror, it affects the tach and it jumps back to normal. It's on my "to do" list to take the dash apart and find the culprit.
Help tracking down rough idle / whacky tachometer issue (video)
in 90-95 WD21 Pathfinders
Posted
My tach has been doing the exact same thing for months now but my '93 Pathfinder runs great. I suspect it's a short somewhere in the wiring harness or a bad ground connection? Sometime when I adjust the electric mirror, it affects the tach and it jumps back to normal. It's on my "to do" list to take the dash apart and find the culprit.