hookedup50, did you take a look at Hewitt Industries? Your post made me think of them. They list an engine protection system (kit 191-500) that will give an alarm and 30 seconds later shut down the engine for low oil pressure, high coolant temp, and low coolant level. Their website claims easy installation, low cost, and made in the USA. When I first saw this shutdown switch it reminded me of a few rides I had in a White Freightliner when I was still in high school.