Reply To: EDMU help
To access the gauge, get a 5cc syringe or air compressor hose and insert it in the small hole on the side of the metal bezel. It may be covered by a black sticker. Be careful as blowing air through the hole will make the black face cover blow out so just be aware. Then use a toothpick and there are at least two or three small indents along the edge of the circuit board where you can use the toothpick to lift up the circuit board from inside the gauge body. Once you do the battery will pop out the back as it’s retained by pressure. You can see if just replacing the battery fixes your issue. Otherwise, refer to the manual link above and use the circuit jumper to reset the gauge.