Sounds like a grounding issue of some sort. Is your grounding point filed clean of paint and what not?
I have a very wierd problem. When I turn my subs on my screen gets wierd white horizontal lines on it. When they are off its perfectly fine. Ill give ya a run down on my setup to help solve the problem.
I have a 25 watt RMS 2 channel infinity amp for the normal speakers and tweeters. I have 1 12' sub with a 500 watt PEAK amp. My normal speakers are ran on left and right in parallel. My speaker wire, and my 10 guage power wire run on my right side. My s-video for my screen, my USB, my power on for the pc, and my inverter and sub power switches are on my left side. All my power is run in parallel, and I have the shortest possible ground. BTW my power on for my 25 watt amp is run off the power inverter's 12 volt line directly so when I turn on my inverter it comes on. My sub's power on is ran off the same line but on a toggle switch. Any help would be apreciated.
yes, I made sure of that with a dremel.
Have you tried to run your sub amp directly to the battery?
Yah hooked up directly to my 10 guage.
how is the screen earthed?
im guessing, via the chassis of the unit to the metal of the car, and i would assume also via the earth wire where does the earth wire go? to the same point as the amp etc?
if it goes to the amp try earthing it to the metal under the dash.
also do you get any engine whine thru the speakers with your lights on when the whole system is running?