Radiator fan in a'92 Plymouth Sundance doesn't come on. Fan runs when connected to the battery and you changed the fan sensor What next?

Run the A/C all the time until you get it fixed. It will run anytime the A/C is on. It has to be a defective thermal switch, or defective wiring, for the fan if the fan itself is good.

I had the same problem and it was a simple $11 relay switch that solved the problem