Homemade gauge test tool, C-3826

Old thread guys! But I have a question about the tester.

MOPAR always refers to a gauge tester to check oil press. fuel level and coolant temp.

Would that homemade tester be able to test a coolant temp. gauge???

I have a 73 Dodge truck, temp gauge doesn't even hit 120 degrees when it's warm. (160) Gauge goes from cold to hot if you ground the sender wire. Sender reads approx. 86 ohms. cold and was reading 31 ohms when I had it around 160 but the gauge was not even at 120.