At 10:19 AM 6/24/2013, Jeff Lincoln wrote:
>No offense Scott but he did say: " read the *original* owner's manual "

Aye.  But he *misread* it, or more likely he's misremembering the
details (which would have been to the effect that an OIL light at hot
idle isn't necessarily a problem).  There's no connection between the
oil pressure light and the brake warning light system.

On the '84 the brake warning lights if the parking brake is on or if
only one of the two pressure switches activates when the pedal is applied.

On the '85 they seem to have done away with the pressure sensing and
only activate for the hand brake.  I think this is unlikely and the
wiring diagram is probably wrong.  I'm going to guess that they went
to the float switch as below.

Starting in '86 they changed over to a float switch on the reservoir,
so in addition to the hand brake the light activates when fluid drops
in the reservoir; but not for a pressure imbalance between the two
brake systems.  To do the job thoroughly they need both.

The OIL light is completely independent of any other system.

Yours,
David