I have owned a Jinma and the switches are not quality and failed quick for me. I would start with a test light fastened to the negative (-) side of battery or engine block and touch the probe to both sides of the light switch terminals when it is turned off and then on.This should tell you if the current is getting to the switch and coming through the switch.You may have to check to see if the current is getting to the fuses on the way to the light switch. If the test light does not light up anywhere you may have to run a new wire from the positive (+) on the battery or the large threaded post on the starter that is fed from the + battery .