Well I pulled the TBI 350 out of the 88 crewcab last night and found two oil switches on it. The oil pressure guage did not work when I got the truck, so I bought a new switch and installed it in the back of the intake. An aftermarket gauge was hooked up there, and the plug from the wiring harnesswas there so it seemed like a no brainer. But the factory gauge still didnt work. Now I find this other switch right over the oil filter, and I wonder if the wiring harness is somewhat universal with plugs in both places.