Bensinger, Greg wrote:
Hey all,
Recently my tach is a bit jumpy. This occurs when cold, it will track the
engine speed, but sometimes it seems to get updated not on a continuous
basis. Once warm, nice and smooth display all the way to redline+
So where does the tach get it's information? Sensor on engine? ECU? I don't
remember seeing any cable for the tach last time I had the display out of
It picks up the signal right off the ignition coil (the low-voltage
side, of course).
the dash? Can it just be the mechanical magnetic mechanism is getting
sensitive to temps in it's old age?
Yep, definitely. If the engine still runs fine while your tach acts up,
it's either the wire from the coil, or the tach itself. Check for
loose/corroded grounds at the coil and inside the cluster, too.
Cheers,
Oleg
