Engine Coolant Temperature Gauge

1. Disconnect the water temperature indicator sender unit connector. Connect one lead of the tester to the water temperature indicator sender unit C131-1, circuit 737 (W/LB), and the other lead to ground.







2. Set the tester to 300 ohms. Key ON. Wait one minute. The engine coolant temperature gauge should indicate C (cold).







3. Set the tester to 45 ohms. Wait one minute. The engine coolant temperature gauge should indicate one quarter to mid-range.
4. Set the tester to 18 ohms. Wait one minute. The engine coolant temperature gauge should indicate H (hot). Key OFF. Return to the pinpoint test.