I removed the tank and the air filter cover and that provided room to reach down in the gap in front of the air box and plug the Eastern Beaver harness connector into the factory option plug. It's an easy route in. Do it when the tank is near empty.I put the OEM heaters on mine recently. It was quite a bit of PITA just to ultimately shove some connectors together.
IIRC, the instructions start with "remove cowlings," and end with pivoting the radiator before you actually start plugging stuff in.
I read a few posts here about it at the time: some people even had to pull the fuel tank and airbox to find it, and it may or may not be taped up to a bundle of wires.