My Automatic 88 Engine Temp Gauge has stopped working, what do I do to
fix this?

Note the blue and black sensors on the thermostat housing were
replaced months ago but for some reason the black sensor does not seem
to be doing it's job.

What could be the fix?

It worked once in the last month after I pressed the sensor in.

Bad wire?

Gauge damaged?

Thoughts?

Robert
NY