I’m new to the 100 and can’t get sound over the FM Modulator. I know the modulator is broadcasting because if it is on all static or weak channel sound on a channel will go away and be replaced with silence, and if I turn modulator off the static comes back. But, no DVD noise. I can get dvd sound if plugging a headphone into the headphone jack on the overhead factory screen. So DVD player sound works as confirmed by headphones, and modulator is putting out a signal as confirmed by radio, no no dvd sound over FM. What am I missing (besides a chromosome)?