Sounds like I have the same digital meter as you. I got mine off Ebay,burnt the first two up as posted in above posts. I got the 5 volt regulator with next set, now I use a 9 volt battery to the 5 volt regulator on each gauge,(Volts and Amps) also got the shunt with the amp gauge. Hooked up well over a year now with no problems. Battery lasts a long time if you put in a rocker switch and dont leave them on all the time.