Ours is a 2005 Monterey, so differences are very possible, so for what it is worth,... I installed the see-level system on our coach using it only for black and gray water. Assuming that your water access and dump are on the drivers side of the coach, move to the opposite side (curb side) and there will be a hinged panel that is not so obvious. You need to reach under the coach and unlatch the cover. Behind that cover you have full access and can readily view the large pipe that goes into the black tank for the toilet.
This is also the side where our original sensors plug into the Aladdin. I mounted our See-level sensors from this side. Made the task a bit easier. Follow See-Level instructions and tape the sensor in place first to try it before gluing permanently.