TEMPERATURE SENDING UNIT TESTING
Tests for the sendig unit must be made with the sender disconnected form the aguge. Leaving connected to the aguge will cause faulty readings as the inside of the gauge will also be read.
The Temperature senders are a brass housing with a thermistor inside. This thermistor creates resistance to ground with changes in temperature. The resistance DECREASES at temperature INCREASES.
To test the sender, use a multimeter and probe the sending unit stud or output wire (red) and ground the other end of the multimeter (black)
You should see the follwing results with 10%: