When I forst start the sled, the headlight/tailight is dim, then as my son rides i will start working correctly and shine really bright. THen as he rides it will flickere back and forth from bright to dim. I have checked all wires going to and from the lights and all other electrical wires around the engine, everything looks good and I cannot replicate by wiggling the wires. Also, there is a little electrical black box on the firewall of the hood compartment. Sometimes, I can tap it and the light will go bright. That is only sometimes. I have an OHm meter, any ideas on what to start OHMing?

Replace the little black box(voltage regulator) and your problem will be solved.