Digital Panel Meters FAQQI have a DCA-20PC-X-DC1-RL ammeter which I believe is properly connected to a +12Vdc power supply, but the LED display is totally off (dark). What’s the problem?

Check to see if jumper J3, located on the rear of the ammeter, is correctly installed for ‘-DC1’ models (i.e., it shorts out the two small pins). ‘-DC1’ models are shipped with J3 installed, which configures the ammeter to operate from +5 to 40Vdc power supplies. When J3 is removed, the ammeter will only operate from +36 to +75Vdc power supplies.