http://www.ebay.com/itm/291369928250?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT i bought this cheap ammeter/voltmeter off ebay. now, i bought 1 before but it was slightly different. the wires had blue red and black instead of blue yellow and green. this makes it confusing but still i never had the problem im having now. so, this one i simply TOUCH the yellow wire and it reads like 10-30 amps. i never had that problem with the other one. what might be causing this? i can get a volt reading fine, but the amp reading is definitely wrong. if i touch it to anything by itself it read like 30 amps. it doesnt do it with everything but anything like a negative or positive part of a battery or just my finger. it reads and jumps around with amps. what is causing this? are the wires mixed up? is it a defective one? cause my other one which was almost identical didnt do this.