PM sent. Please answer my questions above? and here. Why did you not confirm/report the test I gave you? I/E. No reading on either side of reducer? Check the gauge power fuse and any other fuse involved.
The answer is you have something wired wrong, or a blown fuse or bad ignition switch or a bad reducer or you didn't turn on the ignition or the battery is dead or a wire fell off...........to find it, it takes a little testing/tracing/logic/answers from you. It can't be ground because you used a good clean ground on the tester tonight, right? Run a wire from the battery negative post to the tester ground lead when you test for voltage, that will eliminate all chassis ground problems and tell us it is a voltage problem for sure. Is there power to the ignition switch? On the BAT terminal on the rear of switch.
Read the PM too!
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn