I'm trying to DIY a tailgating set up to run my TV audio through an old car stereo (not installed). The stereo is a Pioneer DEH P-3300 powered by a computer power supply unit (yellow to power, black to ground with the green spliced into the ground). The TV is a 32" Vizio flat panel LED with a headphone jack audio out. The TV audio out is connected to the stereo through headphone jack to the Pioneer IP-BUS input. When I connect the set up to my phone or iPod, the sound is clear, no noise. However, when I connect the set up to the TV, I get an alternating hum. I suspect it is a ground loop issue based on my research. Wondering if anyone has any other ideas. Thank You.