temp sensor with autometer gauge

The coolant sensor that is in the piping to the heater core is what the computer uses for temp readings for the fan. The sensor that is on the driver side is for the dash gauge.

I thought I answered this in a PM on the Corral yesterday?

To answer your latest question, the EEC has no clue if the gauge's sending unit is connected or not. It cannot cause a rich or lean condition.

The lack of an ECT can definitely cause a rich or lean condition. You referred to a 'sensor' in the PM. Remember:

sensor = ECT, for the computer and fan. Multi-wires. Passenger heater rail.

Sender = for the gauge only. One wire. Driver's side front lower intake.