Re: Where is this alt noise coming from?
video pieces (like your DVD players) are noisy. You said you "checked" all the grounds. What does that mean? here is the checklist I typically go through when trouble shooting noise......
Head unit (all sources) Grounded at the same spot the amps are grounded ... Yes you have to run a new cable
Amps. All grounded to the same spot?
Is the *ONE* ground location clean? Free of paint and corrosion?
How big is the battery to chassis ground cable? Is it bigger than any other power/ground wire in the car? It should be...
Are your RCA's run as far as possible away from the power wires?
Get XM Radio, it's awesome!