i was wondering if anybody knows where the best place to hook up a ground wire on a 2003 f250? i have the amp under the back seat.

 

I'm not terribly familiar with Fords, but a lot of people use a ring terminal 'round one of the seatbelt bolts. Another option, the one I personally prefer, is to drill a fresh hole in the floor. Use a sanding disc or similar to clear off a bit of the paint around the hole, then use a large self-tapping screw with a star washer to clamp a ring terminal down. If you put a little bit of RTV on the screw where it comes through the floor, it'll never rust.

If you're going to use an existing bolt, I would still sand off some of the paint down to bare metal, just to be 100% sure you have a great ground.

 

To add that said above- seatbelt bolt is often used, but a safety item. Avoid to use it!

Instead of this use a bolt with a self locking nut and correct washers above and below the sheet metal.
Self tapping screws have a huge disadvantage: with time they start to corrode.

The ground bolt is only 50% of the work!

The ground wire should be as short as possible and the diameter must be the same as the positive wire.
Don't forget the battery ground cable. You have to add the cable diameter to the already existing ground cable to make sure you can transfer the power.

 

I always run my grounds back to the battery. I also just the samne size wire or one bigger than the power wire

 

This is waste of copper(money) and absolute unnecessary.
Even the resistance is mostly higher than a direct short ground connection.

Sadly enough this done by a lot of installers- simply reason, it pays of into the dealers pocket to sell these 15 expensive feet of hyperduper superwire.

 

Well stated couldn't have said it any better.

 

Taken from Welcome to teamROCS

"In the noisy and imperfect world of car audio, proper grounding is essential to the SQ and lifespan of your system. In this paper, I will outline proper grounding techniques.

First of all, make sure that your ground cable(s) are the same gauge as your power cable(s). Remember that all of the current that your amps are drawing has to go somewhere, and that somewhere is ground.

Second, make sure that your ground wires are as short as possible.

Third, when attaching the ground cable to the ground, make sure that the spot you choose is bare metal, not painted, and that it is connected to the frame. Checking continuity between the ground (black) post on your battery and the ground point you have chosen is a good idea. You should also consider upgrading the ground from the battery to the chassis, specifically, running a very stout wire to the firewall.

Finally, when grounding multiple amplifiers, try to using the same ground point for each of them. This will minimize ground-loop problems. If you have a multiple amp setup with ground-loop interference, try moving the grounds around. This should clear up your problem."

I agree that "super-uber" (Monster) wire is a rip. Just make sure you're using a proper gauge wire for the combined load (current [amps], not voltage) you are throwing at it. The higher number of strands the better!

 

Higher strand count is valuable only for flexibility, which is only valuable at the install time. Welding wire is your friend when you need 1/0.

 

I agree that welding wire is an excellent source for multi-strand 1/O cable. Flexibility is a very valid point to do a clean install. There are many places that a DIY'er can buy good quality wire without having your wallet raped by the local stereo install shop.

 

well thanks for the info, i'll probaly run a wire to the frame from the battery, and hook up the amp to the cab.