The Oldsmobile Connection

[Brando]

The ground for the amplifier should be directly to a bare metal area of the car body, within eighteen inches of the amp's location. The ground wire should be the same gauge as the power wire.

* The best method for attaching the ground wire to the car body is to find a convenient location as close to the amp as possible. An existing bolt or screw can be used secure the ground wire terminal directly to the metal body of the car, or a self-tapping screw can be addded. It is recommended that you use sandpaper to remove any paint that may be covering the ground point, so as to give direct contact to the metal of the body.

* Always use a ring terminal crimped or soldered to the end of the ground wire, and not just bare wire.

* If it becomes necessary to drill a hole to accept the ground screw, take care NOT to drill into the gas tank, gas line, or brake lines.

* To reduce the likelyhood of noise, avoid mounting the amplifier chassis directly to the vehicle body. Instead, mount the amp to an electrically insulated material such as a wooden board, carpeted area, or plastic surface.

[sectrix]

A few other things: A car chassis is about equivalent to a 4 AWG cable. If you are running large amounts of current, IE if your power wire is larger than 4 gauge (thicker), then it might be a better idea to run a seperate ground cable back to the battery for best performance. Also, if you do use the chassis ground, make sure the ground wire between the alternator and the amps is at least as thick as your power cable.

[88 Coupe]

Hi sectrix, hello everyone,

Quote: ........ A car chassis is about equivalent to a 4 AWG cable........
Sounds pessimistic to me. My experience says, at least 00.

Regards, Norm

[andrewk]

sectrix wrote: A few other things: A car chassis is about equivalent to a 4 AWG cable. If you are running large amounts of current, IE if your power wire is larger than 4 gauge (thicker), then it might be a better idea to run a seperate ground cable back to the battery for best performance. Also, if you do use the chassis ground, make sure the ground wire between the alternator and the amps is at least as thick as your power cable.

I would agree with Norm here, but wouldnt the ground be as good as the ground cable to the battery? Or am I thinking too hard?

[88 Coupe]

Hi andrewk, welcome back.

andrewk wrote: ........ wouldn't the ground be as good as the ground cable to the battery? ........
Yes, cables are the weak links.

sectrix wrote: ........ if you do use the chassis ground, make sure the ground wire between the alternator and the amps ........
Chassis ground using a wire to the alternator?

sectrix wrote: ........ is at least as thick as your power cable. Brando wrote: ........ The ground wire should be the same gauge as the power wire.........
I thought Brandos post covered it very well.

I prefer soldered connections for sound systems, but crimped work just fine.

Regards, Norm

[DrRansom442]

I will back up Brando, Andrew and Norm here....since your battery grounds to the chassis (well OK most likely the engine - same difference its chassis ground) it would stand to reason that grounding directly to the chassis makes most sense. I personally have never seen someone route a negative battery cable from an amp(s) back to the battery {can't imagine why you'd want to either} perhaps if the battery was trunk mounted and within 18 inches of the amp(s), even then I think I'd prefer a chassis ground...myself, I've usually found a nice solid piece of metal (like the brackets for the trunk hinges), test it for a good ground and make sure it will not cause interference with operation, tap a hole, sand around it and stick a stainless bolt with some nice large washers (on both sides of my mounting hole)/nylon lock nuts to keep it from working loose. (Now you have a post in the trunk good for any other grounding that may come up later)

[88 Coupe]

DrRansom442 wrote: I will back up Brando, Andrew and Norm ........
Interesting post, considering its timing.