Hi, sorry for the delay. If the leds come on as zeros, display “0”, this should be wired incorrectly. if the gauge display “1”, it should be overrange, more than 10A, the measurement range of the gauge is 10A.
If you can please have the THIN black wire vacant, do not connect to anything, just connect the black wire to the battery’s negative lead and use the yellow wire as the (new) negative lead (wiring the meter in series).
If you still have any other questions, don’t hesitate to write back to us.
Best regards,
DROK