Philips screw to ground and, drum roll please, no light.
So, bulb, connection or diode.
The diode is working for the clutch safety wire that goes in the other side of it. Is it possible the neutral switch side is bad? Any way to test a two-prong diode with a multimeter?
If I hook the positive side of a voltmeter to the wire coming from the bulb/idiot light and the negative to ground, it shows 12.36V. Doesn't this mean the bulb is good? If not, I can just swap it with the good oil pressure indicator bulb to verify.
Otherwise, I guess I could pull the wiring harness off, unwrap it, and start checking . . . that sounds about as fun as a root canal.
Speaking of root canals, I've gotta take my 11-year-old daughter and four of her friends to dinner and a movie. So, I'm going dark for awhile.
Thanks for all your help!