Quick ? about the H4 headlight upgrade - ground circuit.

If you are using H4s pls confirm you are using a relay harness too - ie your headlight or high beam circuit (red & purple) is only sending +12v to energize a relay that is supplying the current to the bulbs? Do not use your stock headlight and dimmer switch to power H4 bulbs - period. In these H4 harnesses, whether you buy it or make it (plenty of diagrams online) the dedicated ground for each bulb is run in the harness and generally routed out and ganged to a terminal ring that you put under the bolt on the core support where the rest of the forward grounds go. The hot lead for the relays is usually paired to the starter solenoid always hot stud. Makes for a clean harness install and you know both hot and ground are sized for the H4 load (prefer 12ga but 14ga is adequate).