Gone are the days of craning our necks to see blind spots or using paper maps to find our way you can now customize your car or truck with thesewiring diagramtheories, to have a reversible camera display and GPS installed.
Next, installing a GPS thats bolted into the dash as opposed to having wires everywhere.
During your installation remember that the power source is connected to one side of a coil and the ground to the other when 12V is applied it creates a magnetic field that closes the switch.
PwrRngr
Yes the grounds are necessary on the relays. The power source is connected to one side of a coil. The ground is connected to the other side of the coil. When 12V is applied across this coil, it creates a magnetic field that closes the switch above. Without the ground, the relay wont do anything.