rangerteret

After a LONG drive to LA and Freeway trip of 120 miles,normally not done,My Oil Pressure gauge needle started to "twitch" or "Flicker",slightly!After I came to a stop at idle the gauge would flicker!Oil is clean and correct(5W20,2002 Ranger XLT S/C 4X4 OffRoad/V6 3.0 L. 75000 miles.It doesn't do this on my usual trips:22 mile roundtrip to nearest convenient store or 50 mile roundtrip to town! This was a VERY Hot Trip (Record Heat),Long Freeway speed driving,Stop,foot on Brake and Oil pressure gauge needle "Flickering"!I finally found out Where it is,after EXTENSIVE searching,and Haynes manual,doesn't mention it!,But Chiltons shows it on lower engine breakdown schematic! My main problem is neither book says a good way to get to it! I understand from a part search for the Oil Switch,a socket of 15/16 in. is req'd? They sell 5 inch deep wells and others,I will probably have to get one which is not bad$ wise since sender is $7 or so and socketabout same.I can see it through the "hole " in left fender well liner where I remove mud flap and use a "trouble light",but How To get at the Sender?No room to maneuver!Uderneath or above,even standing on a 3 fooi step ladder ,over the engine! HELP!