Grounding point for an amp in e30

[efirty 0]

Like the title says, i have been trying to find a good location to ground my amplifier.

But every place i have tried has been unsuccessful so far.

Any help would be appreciated!

Cheers, Josh

[Katalyst 0]

bro pick a bolt near your amp, and make sure its part of the main body, sratch away all the paint (most important part) arond the bolt area, then bolt it with lug terminal betwenn car body and wotever the bolt holds to the car, and bolt up really tight

and shuld be done

also if u have a soldering iron tin the ends of your wires makes them better, also a good size cable helps aswell

[bravo 35]

Also, on my e30, there's a grounding point by the aerial in the boot.

[OLLIE 26]

Also, on my e30, there's a grounding point by the aerial in the boot.

what he said - aerial grounding point

[efirty 0]

Also, on my e30, there's a grounding point by the aerial in the boot.

Cheers bravo, didn't realise there was a grounding point there

[M325is 0]

Somebody grounded my amp to the back of the rear seat (in boot) so its verticle. Not sure if this is ok though.

[320guy 0]

I grounded mine to the shock tower.

[Brennan 0]

if its in the boot is there anything wrong with running the ground cable back to the neg terminal on the battery?

[bravo 35]

Somebody grounded my amp to the back of the rear seat (in boot) so its verticle. Not sure if this is ok though.

The amp should have a ground wire - not be gounded through the amp chassis. Cheaper amps will not have proper internal earths and so you may get an earthloop if the amp is mounted on metal part of the car. If you're not getting alternator whine then you're probably fine and so its sweet.

I grounded mine to the shock tower.

As long as you clean the paint off the tower this should work ok. But make sure the shock tower bolts are torqued correctly. Although you'll probably get away with it, it has been known for overtightened shock tower bolts to break as they are under too much tension, and loose ones to loosen esp as the nuts are one-use.

if its in the boot is there anything wrong with running the ground cable back to the neg terminal on the battery?

Not per se, but its good practice for the gounding to go through the chassis to the battery - someone will be able to explain the physics, all I know is that I've always been taught its a good idea.

Edited April 11, 2007 by bravo

[cainchapman 0]

I'd disagree on the earthing through the Chassis.

Ideally you should have all the earths at a single point. As this means a lot more cable (and suitable sized and shielding, if needed) then the automotive industry takes the shortcut of using the chassis as an equipotential bonding point.

Also the reason for the battery being near the engine in your car. Heat is the natural enemy of battery life, so why put it in the engine bay? Cabling.

[bravo 35]

Like I said Cain, I don't know, its just what I've always been told. May have something to do with the fact that most of the time, the audio is on when the car is running which means you have an alternator in the equation also.

Aside from that, here's a few tips stolen from probably one of the most technical car audio sites www.bcae1.com

Note the comment about amps producing less power if there is greater resistance in the return path - may back up your point about going straight to the battery - line of least resistance.

Vehicle Floor Pan:

The vehicle floor pan is, on many vehicles, a single piece of stamped sheet metal that runs from the trunk of the vehicle to the firewall. It is the best return path of the vehicle's chassis. When you ground any electrical accessories (including your amplifiers), ground them to the floor pan. Do not ground anything to braces or the wheel wells. These pieces are generally connected to the floor pan with a few spot welds. If you ground to any spot welded sheet metal, you will have more resistance in the return path. The floor pan will have less resistance. Any extra resistance will lower the voltage at the amplifier and your amplifier will produce less power.

Note:

The seat belt bolts are rarely a good place to ground your equipment. Sometimes there will be a thick tar like substance (used for waterproofing) that will prevent you from getting a proper ground. Even if there is no sealant, the connection may be less than perfect because the hardened steel seat belt bolts (relatively high resistance) go into a hardened steel nut that's pressed into a piece of stamped steel that's spot welded to the bottom of the vehicle (not exactly a great electrical connection).

Edited April 11, 2007 by bravo