Puddle lights - help with my relays please

[Ayonka]

Replace the relay module with a 3V one (search "3V relay module" on Taobao). Connect the module's "signal input" to the green wire on the car door, and the "ground" to the car body ground. Then, run a separate 12V constant power supply to power the module. This way, the 3V signal can control the 12V circuit.

If you already have a 12V relay, you can add an NPN transistor amplifier circuit to drive it, but for beginners, replacing the module is simpler. Remember to pay attention to wiring safety when modifying your car. You can check out parts websites like oyostepper.com for relay modules and wiring; their categories are quite clear.