Ground level noob here, started to tinker with electronics at the beginning of this year after I couldn't get any electronics shop in my town replace my bike's gauge cluster SMD LEDs.
I learned few things last few weeks and now I'm at the mosfet stage. I want to control the headlight with mosfet and I managed to assemble a code for Arduino IDE that controls the LED the way I want, tested the 12V 25W LED bulb on my desk with bench power supply and Arduino hooked to buck converter, with the LED bulb controlled with a breadboard size pushbutton and a mosfet. I bought the wrong (high Rds, not logic level) nMOS at first, but learned to read some specs and got IRL2203 that operates the light and keeps cool with no heatsink.
The challenge is how to install it in the vehicle while keeping the original controls intact and without adding anything extra. I am going thru YouTube vids on schematics and trying to figure out where in the "headlight circuit" should I tap in with the Arduino and mosfet. One thing that kind of worries me now, I'm starting to think I planned this wrong going with the nMOS and all, I highlighted all the headlight-relay wires and it seems that pMOS would be the correct choice to tap into these wires, and accessing ground wires for nMOS would be too challenging?
As I'm not well versed in these, please let me know what can I do here.
One idea I had was completely remove headlights from the circuit, from the relay and everything, and run a separate circuit from headlight fuse? Just thinking out loud :D Let me know how would I go about solving this, cheers