Where is the coolant temperature sensor located on an 1989 F150 I6 4.9L engine?

The coolant temperature sensor (CTS) on a 1989 Ford F-150 with the 4.9L I6 engine is typically located on the intake manifold. It's usually near the thermostat housing, but not always directly on it. It's a one-wire sensor and is a relatively small part, often with a single electrical connector.

Because the exact location can vary slightly depending on the specific configuration of your engine, it's best to consult a repair manual specific to your year and engine. A Chilton's or Haynes manual will have diagrams showing the exact location and will also assist with the removal and replacement process. You can also find diagrams online by searching for "1989 Ford F150 4.9L engine diagram".

Looking at pictures online of the engine bay of a similar vehicle will also greatly help you locate it.