I recently purchased an Fm modulator to go with my new head unit that doesn't have an aux input. When the computer is on i hear the music but there is a very loud staticy sound with it. Its not the fm modulator because i've plugged a walkman in instead of the computer and the sound is crystal clear. Also, when i've tried connecting to computer to a power cord from inside the house the noise is gone and it sounds fine. I've grounded everything to the same point and tried to attach the power inverter to the battery, acc wire and cigg lighter but the same thing happens. any suggestions?