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<blockquote data-quote="helotaxi" data-source="post: 1764882" data-attributes="member: 550915">There are a lot of really smart people out there that would call you both ignorant in regards to what constitutes a good ground in a car.First let&#039;s define what &quot;ground&quot; is.&nbsp; Ground is a point of zero voltage potential.&nbsp; In a negative ground system, which most all cars are, the negative battery post is the definition of ground with the car off.&nbsp; With the engine running, the case of the alternator is &quot;perfect ground.&quot;&nbsp; Since the alternator case is connected to the engine block and the engine block is connected to the negative battery terminal through a fairly low resistance path, the neg battery post is still a very close approximation of a perfect ground.&nbsp; The reason that connecting your amp ground to the chassis of the car completes the circuit and allows the amp to function is that the chassis is also connected to the negative battery post and acts as a conductor to ground.&nbsp; It is not a perfect ground however.&nbsp; Steel is 10 times more resistive than copper.&nbsp; This means that the area through which the current will actually flow, must be 10x larger through the chassis to have the same resistance as a copper wire of a given size.&nbsp; There are several experiments published on this matter conducted by various companies and persons and the general consensus is that that depending on the car, the best possible trunk grounding point could vary in resistance from being the equivelent of as small as a 4ga wire to as large as a 2/0.&nbsp; The bottom line is that if you are unsure and don&#039;t have the time or energy to seek out the absolute best ground spot in your trunk and then test it to see how good it really is, just run a ground right back to the &quot;perfect ground,&quot; your battery neg post.To the original poster-make sure that you have the subs wired correctly and that the gains are set correctly.&nbsp; What warning light is coming on when the amp shuts down?</blockquote>

[QUOTE="helotaxi, post: 1764882, member: 550915"] There are a lot of really smart people out there that would call you both ignorant in regards to what constitutes a good ground in a car. First let's define what "ground" is. Ground is a point of zero voltage potential. In a negative ground system, which most all cars are, the negative battery post is the definition of ground with the car off. With the engine running, the case of the alternator is "perfect ground." Since the alternator case is connected to the engine block and the engine block is connected to the negative battery terminal through a fairly low resistance path, the neg battery post is still a very close approximation of a perfect ground. The reason that connecting your amp ground to the chassis of the car completes the circuit and allows the amp to function is that the chassis is also connected to the negative battery post and acts as a conductor to ground. It is not a perfect ground however. Steel is 10 times more resistive than copper. This means that the area through which the current will actually flow, must be 10x larger through the chassis to have the same resistance as a copper wire of a given size. There are several experiments published on this matter conducted by various companies and persons and the general consensus is that that depending on the car, the best possible trunk grounding point could vary in resistance from being the equivelent of as small as a 4ga wire to as large as a 2/0. The bottom line is that if you are unsure and don't have the time or energy to seek out the absolute best ground spot in your trunk and then test it to see how good it really is, just run a ground right back to the "perfect ground," your battery neg post. To the original poster-make sure that you have the subs wired correctly and that the gains are set correctly. What warning light is coming on when the amp shuts down? [/QUOTE]

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