I have a 1999 Dodge Dakota 3.9. I think I have located the ECT sensor, but the one O'Reilly's sold me is a lot smaller on the Hex section. I hesitate to take the one out before I know I am in the right area of the engine.
I think it is located on the right front side of the manifold just behind the alternator. Am I right? Has a black plastic connector on it.

Thanking you in advance.

 

Welcome to the forum.

Right side, behind the alternator is the correct location. Aftermarket sensors can be different in appearance.

 

Thank you. Can this also be called the IAT Sensor? I am confused.

 

The IAT and Coolant Temp Sensor look almost identical on the 3.9

The IAT has a small hole on the bottom of the brass and is slightly bigger.

The Coolant Temp sensor has no hole on the brass and is smaller.

IAT:
dbc01508-3895-45dd-898e-eb99f45a8930_zps56159caf.jpg

Coolant Temp Sensor: Note the back of the alternator on the right side
0049b430-8cb2-45c7-8bd3-d56a26c153ce_zps1a3eaec1.jpg

Here's a side by side comparison of the coolant temp sensor and the IAT
NOTE: This is the 5.2L Coolant Sensor, the 3.9 sensor is smaller:

IMG00237-20111216-1906.jpg

 

Oh, thank you so much! I love pictures. They make things so clear. Now I have to get the air compressor hose out to the truck to blow all the maple seeds, etc. from around the area so I can get to the part.
Not gonna' happen today. Raining, windy and cold here! Plus I have to re-sew the sleeve and sew the sleeve back onto the glove on my husband's sand blast glove.

Ardis
Western Washington State

 

No problem.

Easy job, but bit of a pain to get to.

Lots of stuff in your way - good luck!

 

Can the vehicle be driven without the ECT sensor in place?
2002 Dodge Dakota 3.9

 

No, lose coolant.