Our rig had a color camera and monitor but the image was dimming - hard to see when driving with sunglasses on. Replaced both. Much better now. Anyhow, when I finished the job and proceeded to the now-it's-time-to-turn-it-on stage, I pushed the button and... nothing. WTH (heck!) Now, what. Start batteries on line. Check. Master switch enabled. Check. No fire to the hot...