Well, I replaced the red LED today, and it still didn't come on when I
turned the ignition switch.  I took the negative terminal off the battery
and checked pins 12 & 13 on the instrument panel plug for continuity with
ground.  (According to my Haynes manual, pin 13 should be the output of the
low pressure sensor on the engine block.)  Both checked out at 0 ohms to
ground, so I figure the warning light circuit is getting a good ground
signal.  What's left is some sort of control circuit that is not described
in my manual.  Can anyone shed any light on what this circuit does?  Might
there be a fuse that is eluding my detection?

Thanks in advance.

Dave in KC
85 Westy
http://members.fortunecity.com/davebaker1