Temperature Gauge: Description and Operation
With the ignition switch in ON (II) or START (III), voltage is applied through fuse 13 and the fuel and engine coolant temperature gauges. The gauge circuit is grounded at G402.The Engine Coolant Temperature (ECT) gauge is divided into 7 separate segments. The number of segments that light up depends on the input from the engine coolant temperature (ECT) sending unit. The sending unit's resistance varies from about 142 ohms at low engine temperature to between 49 and 32 ohms at high temperature (radiator fan running).