head unit does not work when lights are on

[synthply]

I just installed a head unit in my car during the day today, and it worked fine. However when I had to turn my lights on the head unit now flickers and the sound is intermittent. So basically it works with the lights off and does not work when the lights are on. Can anyone help me with this? Thanks

[eLKuRLy]

sounds like you probably got the wrong cable to ground it. you probably tested the wire and it showed ground -, so u just used it. but i bet it was the dimmer. the dimmer wire shows ground when your lights are off, and throws power when you turn on ur lights. this wire dims the stereo lighting when u turn on ur lights so it's not too bright at night. the stereo still works, but not properly because it has ground from the antenna. anyway,
sounds like you need the ground it correctly.
hope this helps,
carlos