Is the coolant tempeature sensor, the same
sensor that runs the guage on the dash ?

Or is there another one somewhere?

It's a 1987 2.9l bII

 

There are two coolant (engine) temp sensors. One operates the gauge in the dash, and the other sends a signal to the ECU/ECM. The one for the gauge has a single wire going to it, and the one for the computer has 2 (or 3?) wires going to it. The gauge one is on the driver's side of the water outlet (where the upper radiator hose goes to the engine), the computer one is on the passenger's side, or closer to it than the other, if that makes sense?

 

Hate to bring up a dead thread, but my Haynes manual shows where the gauge sensor is, but I cant seem to find it. It says its on the intake manifold, but Im just not seeing it.

 

Look right above the thermostat housing, next to the heater hose nipple. About the 11:00 position.