Does anyone know what pressure this switch closes? Mine is leaking and I am thinking about getting just a generic one.
There's a couple different ones depending on which filter unit you actually have. Can you read the numbers stamped on it? According to the book it should be marked M4004-40 or possbily -60, I'm guessing here but that mey indicate either 40 or 60 psi. You don't want a switch with a higher pressure spec than the bypass valve inside the filter head, the light should be on well before the filter clogs up enough for the bypass to open, except when the oil is cold.