Engine Temperature Gague inop

I have a 1996 Ford Windstar GL 3.0. The engine temperature gague does not work and always reads off-scale low. Has anyone had this problem before? Is the problem likey with the dashboard gague itself, the wiring, the fuse box, or the actual engine temperature sensor unit. Just trying to get an idea of where to start.
Thanks

For the analog instrument cluster, the circuit is from the battery, through the Fuse Panel to the instrument cluster. In the cluster, this input connects to the temperature gauge, then exits travels through several connectors and wires to the Engine coolant temperature sender, then more wires and connectors, then ground. The resistance of the sender is 74 ohms cold & 10 ohms hot.

Low reading all the time suggests that there is an open circuit between the cluster and ground. Check for voltage at the connector to the sender. One pin should measure 12 volts, the other should measure 0 volts. The zero volt pin should also measure a low resistance to ground. Also check the resistance of the sender. It should be less than 100 ohms.

Based on what you find, you should be able to determine if the fault is between the sender and the instrument cluster or the sender and ground.

In my experience, parts that move or travel thru sections (firewalls, frame sections) are where these problems tend to crop up. Years of rattling around wears the jacket on wires and then you have a trickle to ground. I'd be checking those areas carefully. I've found more wire chafes in my years than bad components honestly.