I have one 15" L5 in a 1997 toyota camry with a hifonics brutos mono amp, the ground is reading out 0.00 ohms for resistance. There is no voltage drop, its getting constant 14.2 The turn on lead is fine the amp is turning on, and the rca's are plugged in. The sub is dual voice coil 2 ohm. We have them wired at 1 ohm. The amp is stable at 1ohm. Please help