In the process of swapping a 1999 TJ 4.0L OBD2 engine into a 1994 XJ 4.0L HO. With this swap we are retaining the XJ wiring harness. It appears the OBD2 engine has no temperature sending unit. Can't see one anywhere. From the factory the head has not been drilled and tapped at the rear of the engine to receive the sender as with the OBD1 motor. Who knows anything differant?