Have you measured the voltage from both sources? Is it designed to blink at a specified voltage reading? Is there a separate wire that senses the voltage and one that powers the gauge?

Steve

 

Manufacturer told me it is not design to blink. Also it only has power and ground

 

Good point Jim.

With my Autometer gauges I sense my battery voltage at my main power distribution point which is constant hot and a separate ignition hot wire turns the gauge on and off. There is a 3rd hot from the lights for the illumination and of course there is the ground wire.

So on yours with only one hot and one ground you must connect the hot to an ignition source. The gauge must break these functions down internally somehow but how does it know when the headlights are on so it can dim the display? There is a lot of electrical noise on the ignition side like Jim said.

I think I would call tech support.

Steve

 

I wonder if it's seeing a voltage spike from something like a coil on a relay.

Jim