2.3 Fan Trigger Switch In Block

What year Mustang.

My 89 2.3 car has an electric fan. There is a temp sensor for the fan, the gage and the computer.

The fan is powered via a separate module under the dash, in 89. Its called an IRCM iirc. I think later it moved under the hood.

On the 89, when the module detects the right temp from the sensor, it turns on the fan via a relay in the box. Since the relay is under the dash and full fan power runs to the box and then to the fan, the wiring and connectors get old and dirty, and the heat from the fan current will melt the connectors. They sell repair kits...

The fan has power switched, not ground as far as I know.

I fixed it by using the fan power wire to operate a new relay under the hood.