Noticed no one with a Jayco had replied, but most have similar plumbing. It could have been changed but, on a 96 model you should have a hose connection to connect to city water, a gravity feed inlet to put water into the tank for when there is no city water and then you should have 2 line drains, one for hot and one for cold. Last, you will have a tank drain.
The tank drain will exit below the tank (possibly through the floor) and depending on the camper, the line drains will exit through the wing extending over the bed of the truck or through the floor if the camper has a basement.
A lot of manufacturers will have online documentation for their campers that shows you where all the valves are. If you can't find a Jayco manual online, Arctic Fox puts theirs on line and it will give you an idea of where things are located.
Hope this helps,