First is yours the five wheel? If it is on the drive side of the trailer find your take fill in port. " were you can carry fresh water". Now on the inside look for a vent. "On my RV the fill port is three feet away from the pump," it should be a 1 to 2 foot vent. take the four screws out and you should find your pump. They hide them good "so you can pay to have it done" so look very good. My pump is under living room bed. hope this helps