Temperature Gauge Accuracy

[eze2bme]

My 1979 43DC has the OEM electric AC temp gauges. I have always noticed a difference between the lower helm and upper helm readings ... about 10 degrees ... with the lower helm reading higher. Over the years I've used an IF heat gun to check the temps of the br*** sending units and determined that the upper helm gauges are more closely accurate.

Last weekend I finally decided to install manual temp gauges in the engine compartment ... and sure enough the upper gauges are close to accurate and the lower gauges showing about 10 degrees hotter. Now I can at least run her more comfortably knowing what the actual temps are.

Does anyone know if these AC temp gauges have any sort of adjustment screw on the back????

 

[Genesis]

Nope - its probably resistance in the wiring. Reterminate and clean up the connections to the wires involved and see if it goes away.