Removal & Installation - Ford Ranger Maintaince And Repair Manual

1. Remove the coolant temperature sender from the engine block.
2. Attach an ohmmeter to the sender unit as follows:
1. Attach one lead to the metal body of the sender unit (near the sender unit's threads).
2. Attach the other lead to the sender unit's wiring harness connector terminal.
3. With the leads still attached, place the sender unit in a pot of cold water so that neither of the leads is
immersed in the water. The portion of the sender unit which normally makes contact with the engine
coolant should be submerged.
4. Measure and note the resistance.
5. Slowly heat the pot up (on the stove) to 190−210° F (88−99° C) and observe the resistance of the
sender unit. The resistance should evenly and steadily decrease as the water temperature increases.
The resistance should not jump drastically or decrease erratically.
6. If the sender unit did not function as described, replace the sender unit with a new one.
REMOVAL & INSTALLATION
Ensure that the engine is cold prior to opening the cooling system or removing the sender from the engine.
The cooling system on a hot engine is under high pressures, and released hot coolant or steam can cause
severe burns.
1. Disconnect the negative battery cable.
2. Remove the radiator cap to relieve any system pressure.
REMOVAL & INSTALLATION
HOW TO USE THIS BOOK
Temperature gauge and sending unit wiring schematic
Click to enlarge
CAUTION
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