Why is it good to grind off the paint to install the ground from a car audio amplifier?

[Javi R]

Does this give you a better output...or is it do nothing at all?

 

[Hitchhiker]

you want metal to metal contact since metal is a MUCH better conductor than paint.

 

[JMann]

In a larger, higher power set up, A solid ground will make all the difference in the world. In a smaller, lower power system, you may not even draw enough current to notice a difference.

In most cases, It will just cause the amp to run a little less efficiently, limiting the power output to match the amount of current that can be supplied.

In extreme cases, It can cause equipment damage and even fire. As the current draw exceeds the capacity of the ground, heat will be produced as a byproduct.

As a general rule, it is always a good idea to sand the paint from any grounding surface. Whether you are running 150 watts or 15,000 watts.

 

[decibaldude]

Also its best if ground is kept under 3 feet long.putting a ground on a painted surface is like connecting your speaker wires without stripping off the wire.same idea.