I purchased these reverse indiglo guages through procarparts.com, I've seen them in person and they look amazing. I want to install them next week but I only have 1 week to return or exchange them if there are any problems. My question is how do I test the guages outside the car? After I connect the guages to the switch I am left with two power wires. I have a voltage regulator so I can connect the wires to it at whatever voltage nessary? What is the easyest way to test them? What should I set the voltage regulator too? Or if there is another way to test them please tell me.