Under the seat is a plastic tag that should contain the model number of the mower. Unfortunately, the tag has dried out and turned to powder. The only thing I can say for sure is that it was sold by Tractor Supply under the brand name Huskee - the engine is a B&S 20 HP - 460777 / 2276 E1 / 9803265A. The engine has a spin on filter and screwed into the side where the oil filter mounts is an oil pressure cut off switch (P/N 491657) . I do not see a wire from the harness to that switch. I purchased this mower used. I believe the engine to be original to the mower. I need a wiring diagram that shows me how the oil switch is connected. OR - information as to why I would have an oil pressure switch with a wire lead but no wire on the harness.