I was changing the oil on my 2007 Vulcan 1500 classic I just bought. I noticed 3 drain pipes to the rear of the oil filter. One was hanging down lower than the other and it turned out to not be connected to anything. The pipe in question appears to be a slightly larger diameter than the other two and about 18" to 24" long. I've looked through the service manual I have but cannot identify it. Anyone know what this drain might connect to?