Hi Guys
I need advice. I am busy putting relays on the sealed beams and then later gonna put in semi sealed with higher wattage output bulbs.
My problem is the following:
I saw that the indicator lights on the side panels are attached to the lights earth on both sides. I disconnected them and earthed the one below at the battery tray and the other side (passenger side) I earthed it behind the horn which is bolted and earthed next to the radiator. I want to earth the lights the same locations. I saw that the thick negative wire goes from battery to the engine and then there is a thinner one going from the engine where the thick one is bolted to, to the battery tray below. Am I save to presume that my setup will work because the whole car body is a negative. The relays also needs to be earthed. The relays I am installing next to the light that is in front of the battery tray.I am going to earth them also to the battery tray below where that thin wire is connected.

I might be going fuel injection with management later and just want to make the setup so that it will not have a problem with the electronics of the future management.