Originally Posted by drcrougeux
I HAVE AN 1988 325 IC CONV.
TACH SEEMS TO WORK ONLY WHEN IT FEELS LIKE IT...
How is it connected ? all other instruments work.
The SI Board batteries were checked & are ok.
Loose cable ? Is it elec or mech ?
Someone has got to know this.
It's seems to be a common issue.
There are two grounding nuts on the back of the cluster, they tend to loosen
up over time, check yours and tighten if needed.