Diesel Data: Automotive Repair

Electrical Temperature Gauges


This temperature indicating system consists of a sending unit, located on the cylinder head, electrical temperature gauge and an instrument voltage regulator. As engine temperature increases or decreases, the resistance of the sending unit changes, in turn controlling current flow to the gauge. When engine temperature is low, the resistance of the sending unit is high, restricting current flow to the gauge, in turn indicating low engine temperature. As engine temperature increases, the resistance of the ending unit decreases, permitting an increased current flow to the gauge, resulting in an increased temperature reading.

TROUBLESHOOTING
A special tester is required to diagnose this type gauge. Follow instructions included with the tester.