* Engine Block Temperature Sensor (ECT): This is the most common sensor and provides the engine's temperature reading to the PCM (Powertrain Control Module) for fuel control and other functions. This is usually located in the engine block itself, near the thermostat housing. It's often a single-wire sensor. You'll likely need to consult a repair manual or online diagrams specific to your exact engine (5.2L or 5.9L) to pinpoint its location within the engine block.
* Coolant Temperature Sender (CTS) for Gauge: This sensor feeds the information to the instrument cluster gauge, showing you the engine temperature. This is also typically located near the thermostat housing or the cylinder head, but is often a separate sensor from the ECT. It often has two wires. Again, a diagram is helpful.
* Thermostat Housing Sensor (Optional): Some models might have an additional temperature sensor in or near the thermostat housing. This isn't always present, but if it exists, it would be in that area.
To find these sensors accurately:
1. Consult a Repair Manual: A repair manual specific to your 1996 Jeep Grand Cherokee V8 is your best bet. These manuals have diagrams showing the precise location of each sensor. Chilton's, Haynes, and factory service manuals are good options.
2. Use Online Resources: Websites like Jeep forums (like JeepForum.com) or online parts stores (like AutoZone, Advance Auto Parts) often have diagrams or parts listings you can use to identify the sensors based on your engine. Searching for "[your engine size] Jeep Grand Cherokee coolant temperature sensor location" should yield some results.
3. Visual Inspection: Once you've got a general idea from the diagrams, carefully inspect the area around the thermostat housing and the engine block. The sensors are typically threaded into the engine block or housing and are relatively easy to spot once you know what to look for. They often have one or two wires connected.
Caution: Be careful when inspecting and working near hot engine components. Allow the engine to cool completely before attempting any work.
