Urgent: where do I connect ground wire for amp?

Ok, I finally got my amp for my tower speakers and I want to hook it up tomorrow so I can listen to them on the water on Monday. My main question is where is the ground box on a 2001 Malibu Response LX so I can wire my amp. It is an inboard D-drive boat. Any help would be appreciated since my boat is located 45 minutes away.

Another question is: Can I drill into the ledge where the battery sits? Under the dash on my boat is a ledge that the batter sits on, plus room to sit my amp on. I want to put my amp here so it is close to the battery. I dont think drilling into it should be a problem, but better safe than sorry.

You can ground it directly to the negative post on the battery. Because there is really no good place to put the ground on a boat, the battery is really the only place to do it.

I don't know where the battery sits in your perticular boat, but as long as you are not drilling into any wires and not drilling into the exterior hull, you should be fine.

Good luck

First answer is the negative terminal of the battery. There is not really a good place other than that to ground anything in a boat.
Second answer I have no clue, sorry.

Or the engine block, which is the central ground for the boat. That's where the black cable from the battery goes. The easy answer is whatever is the shortest run from your amp, the block or the battery. I know that as soon as I post this, some "guru" will say that grounding to the block sucks, but it is just as viable as the battery.

DO NOT GROUND TO THE BLOCK!!!

why not? no idea why not, just being a smartass

i actually tried grounding to the block on my old boat but couldn't find a good place to do it. You said you have the amp close to the battery, so I would assume directly to the negative terminal is the easiest.

Ok guys, Thanks for the input.

Also one thing to consider is that the longer your ground wire is the more noise/unclean signals you can get. That is why it is the best to go the shortest possible way.

sounds like straight to the negative terminal.

You guys are a great help. thanks

Putting high powered amplifiers can be a little tricky since most of the literature is designed around a metal chassis automobile. Ideally all positive and negative power sources for all the audio system components should originate from the same point. That point can either be the battery if it's close or a set of distribution blocks if it's far. If you connect your amp negative to the block then there is a possibility that there will be a small but significantly different voltage between ground sources, this will not harm your gear but it will produce noise (usually alternator whine) in your audio system.

Simply put the battery terminals are usually the best connection points for the power sources of your audio system.

The one exception is the red lead to the deck, it can come off the accessory circuit or a dedicated switch to turn on/off the system.

Grounding to the battery creates a ground loop, as the rest of your boat is grounded to the block, which is floating slightly above ground depending on the small resistance of the 0 gauge ground lead that goes from the battery straight to the central star ground point of the boat, on the block. Your alternator, dash, head unit, ignition, etc. is grounded to the block, not the battery.

Grounding to the block puts you on the ripple side of the impedence of the ground wire, I hook mine to the battery. Ground your deck seperately from the harness that way you are not in the mix with various other noise generating devices.

It's not the ripple side if both devices are connected to the same ground point. Noise is generated over the "resistor" that exists by virtue of the difference in resistance to ground between the two different ground points. That is the definition of a ground loop. So, either wire an amp ground to the factory ground point (block) or cut your factory harness and wire an amp and head unit ground to the battery.

told ya..

Well I hooked up the amp Sunday and it sounds great. I have 4 Sony 1640h speakers on my tower and they could easily be heard 70ft behind the boat at 22mph. Thanks for everyones help, I finally have a system!