Oil leak, 84 5kS, follow-up

[Michael Spiers <mspiers@greeley.sykes.com>]

A week or so ago I posted about an interesting puddle of oil under the
'84 5kS, and how to get it the 50 miles from here (work) to home.  Well,
I bought a case of 10W30, and it made it home without incident.  A
little digging revealed the problem:  the lower oil pressure sending
switch (as in below the Oil Pressure Switch) has sprung a leak, and was
squirting oil OVER the left fender when I popped the hood.  Cute.
Anyhow, it took me an hour at Carlsen to explain exactly where this
thing was and what it was ("Is it White or Brown?"  "It's blue."  "No
no, it can only be White or Brown."  "It's under the Brown one, and it's
Blue."  "The wire's Blue or the cap of the sensor is Blue?"  "The wire
and cap both are Blue."  "Well that can't be...") and I _think_ that we
established that it's a Low Pressure sending switch, but she wasn't
sure.  Mr. Bentley, of course, doesn't refer to this thing at ALL, and
none of my local parts houses list this thing ("Is is White or Brown?"
"It's Blue."  "No no no, is it White or Brown?"  "Oh man...")  Anyhow,
anyone with a clue as to what this thing is?  Again, it's below the oil
pressure switch, on the left (drivers) side of the block.  The sensor
looks identical to the oil pressure switch that's above it, but is has a
blue cap, and a blue wire going to it.  It's 13 years old, so if there
ever were markings or part numbers on it they're long gone.  Ideas
anyone?  It's my exgirlfriends car, and has been sitting in front of my
house for over a week now.  I wanna get it fixed & get it outta there,
she's got my Explorer & I'm sick of driving my F150 everywhere.  TIA for
any help

-Mike
Fort Collins/Boulder, Colorado
'91 Explorer
'83 F150
'80 IH Scout II
'80 IH Scout II