I don't change that unless some other factor makes using the manufacturer's ground location impossible, and then I route the ground cable to a manifold bolt within reach of the cable.
ground cable under the car. you need a good ground from engine to frame.
check netural safety switch. make sure u have a good clean ground to the battery. check ground at the frame.
Mostly you will see it bolted to the engine.
bad ground
The ground.
No
Physically remove the horn from the car. Ground it to a good ground on the engine, or car body. Attach a lead to the positive ( + ) side of the battery, with the free end, touch the connection on the horn and it should blow( sound ).
The earth (Ground) on any car battery is negative while the live is positive.
Yes you can if the battery is the problem. connect the red on car with good battery to the positive ( + ) terminal, then the red on the dead battery, connect the black to the negative ( - ) on the good battery and the black to a good chassis ground( exposed metal in engine bay ) a good spot is the strut mount bolt.
You can store a battery on the ground, I belive in the old days when the battery case was made from a different material you couldn't. It is an old wives tale that leaving a battery on the ground causes it to drain.
Remove the old ones + battery to starter solenoid - to good engine ground and follow routing the existing ones use
voltage regulator.