I bought used 2010 Coolster 3125 from a friend. I finally got it running.. Now im trying to figure out why the headlight and small bulb has no power. I test the bulb direct to battery, it's fine. I check the adapter and connector, has no power. So where should I look into? Would the voltage regulator be bad? Please let me know

 

Some Chinese machines have lights run direct from the alternator so only work when the engine is running.

However, assuming it draws power from the battery for lights, check the fuse (if fitted). Next check the earth wire to the bulb holders is OK, check if power is getting to the bulb holders, if not check if power (ignition on) is getting to both sides of the dip switch, if not check both sides of the light switch, if not you have a bad wire from the ignition switch to the light switch.