I have bought some 8guage wire to do grounding. However can anyone share, what point to what point should I ground?
Usually a 5 points grounding work for an Auto car... you can install at engine block, alternator body, battery negative, auto gearbox and throttle body. The purpose of having grounding cables in the car is to reduce the resistance/impedence and better electrical flow.
From what I know, the best and lowest resistance/impedence in the car is the car chasis itself so every grounding cable from engine block, alternator body, battery negative, auto gearbox and throttle body are connected back to the car chasis. As for the grounding cables on the body chasis, you need to scrap off some paint where the grounding cables are screwed on. Do remember that the layers of paint on the body chasis is also resistance/impedance.
Also why I do not connect every grounding cables from engine block, alternator body, battery negative, auto gearbox and throttle body directly back to battery negative terminal is, the reason is that the longer the cable, the higher the resistance/impedance unless you use thick and better quality of grounding cables. Which is why, if you are using 8 AWG cables, try not to use long grounding cable for each point. Ideally, try to keep each grounding cables from 30cm to below 50cm long....
Do take note that it is important to use quality Oxidise-Free Cable (OFC - some quality cables comes with 99.99998% OFC and not necessary from branded grounding cables like Pivot/D1Spec and so on....) or otherwise, over a period of time, oxidation will take place along the copper wires which will result higher resistance/impedance (in other words, it is like not putting grounding cables in the 1st place or worsen the problem).
