I was installing the UPR EL-glo gauges from Mustangtuning and I didn't hook the wires up correctly. Which wire is the power and which wire can I tap into for the ground. I can't find a darn bolt to ground so I was going to tap into the black wire on the gauge harness. I hooked up the power to the solid brown wire but it didn't do anything. Anybody have an suggestions? Thanks.