Does it make a difference how long ground wire is ?

[Kavehman]

I want to locate my amp somewhere else in my car, I am wondering if it makes a difference if my ground wire is longer than the one provided originally by the wiring kit

If it does, ideally how long should my ground wire be ?

[Kyles ej1]

the only difference it will make is if its not long enough your amp wont turn on

[EBP_SI]

ideally you'd like to keep all the wiring as short as possible. where did you plan on mounting your amp that doesnt have a possible ground spot close by?

[D'Ecosse]

Originally Posted by Kavehman

...If it does, ideally how long should my ground wire be ?

It does make a difference- you can get as much voltage drop across the ground wire as you can on the positive supply.
Relocating your sub shouldn't be an issue though - wherever it goes, you want to make the ground wire as short as possible (say ~ 18") and ensure you have a good solid connection to the chassis. Make sure you clean any paint off your ground point with some emery cloth and use a star washer to get good "bite" between the terminal & chassis. Bolt it solidly to the body with bolts, lock washers & nuts - no puny sheet metal screws!
Best thing is to use a proper grounding terminal, like one from stinger or whoever takes your fancy. The wire gauge for the ground should be at least the same as that for the power.

[Kavehman]

thanks for all the advice guys, I had the amp mounted on the back of my box, i moved it so its sitting in a more vented area, i had to lengthen ground wire byabout 3 inches for it to fit, so i dont think i have affected it that much.

Thanks a lot