Big Mack

iTrader: (1)

False. False false false. You do not need to run a cable from the trunk or other mounting location all the way to the battery for a quality ground for an amp. You do, however, need to understand that paint is not a conductor, nor is rubber, plastic, or grease, or anything else that may be under an existing nut or screw near your amp or deck. A proper ground will not only be the same gauge as your power cable, it will be secured tightly with a bolt or heavy screw and star washer to ensure contact in all areas. This is done after you scrape anything/everything away from the small area that will be making contact with your terminal that is connected to said bolt/screw and star washer, and, ideally, is as short as possible since power flows from negative to positive in the automotive environment. Factory grounds for decks can be good or bad, it really depends on whether or not the vehicle uses a metal cage for the deck, thus creating a ground simply by touching the chassis of the deck to the mounting cage. If you have noise, a different ground for the deck may be needed.

Combine this with proper grounding under the hood, as stated above, and you should have no ground concerns with amps or decks.

Big Mack

hihopes

iTrader: (7)

id think that if it goes away when your pc is on, that you wouldnt have to ground the pc better, but the stereo system instead. with my problem, whoever installed the old headunit just completely disregarded the ground wire coming from the stock wiring.
i would take out the headunit and check to make sure all the wires are connected in the first place. if theyre all good, then you can try putting the ground wire on different things and see if it improves.