I have a question for a friend with a 2001 Cummins 24V with A/T: he has an erratic oil pressure gauge and was considering replacing the sender. A shop told him that it was integral to the pump and in the end would cost him $800. 00 for the part alone. I'm a 12'er so I don't have ready resources. Anybody, where's the sender, what's a typical cost?? Many thanks.