Review on Sierra International Oil Pressure Sender (OP72533) - Enhanced SEO-friendly Product Name by Jeremy Jackz

Purchased as an alternative to the Carter A68301 Fuel Safety Sensor. First, Carter has a 1/8" NPT threaded fitting, while this assembly has a 1/4" thread (not mentioned in the product description). So if your oil pressure port has 1/8" NPT threads like I do, you'll need to add a few extras. pipe fittings. The unit I received was defective or not a genuine replacement. The Sierra OP72533 has the same pin markings as the Carter but the block I received had no continuity between the P&S contact points. Not sure if this was an isolated incident but the fact that I add extra fittings does had to make it work wasn't worth replacing with another unit. Without a P&S contact (normally closed) your fuel pump won't turn on until the boat goes bad and tries to boot the boat with an empty carburetor chamber to start.