The vehicle was on as I was using the 12V from the power outlet in the center under the dash. The audio was very distorted. I'm sure it was rf getting back into the radio as the audio was clearing up hen I lowered power. Antenna was too close to the radio. Had a similar issue with the Icom 706MKIIG in my Honda Accord. Had the radio up front and the antenna on the trunk lip. After I moved the radio into the trunk it worked perfectly. May also be a grounding issue, as the radio was sitting on the passenger seat and I didn't crank the lip mount screws down unless it was going to be a permanent install.