The oil pressure switch is located between the carburetor and the firewall on top of the engine. You will need a 9/16 open end SHORTY wrench to remove it.
Oil pressure varies but should normally be around 40psi
on an 87 bronco with a 351w (5.8) its on the drivers side right above the oil filter.
The oil capacity for a Ford Bronco is approximately 5 quarts of oil. The recommended oil type is 10 W 30.
According to the 1996 Ford Bronco Owner Guide : With engine oil filter change : ( 6.0 U.S. quarts , 10W-30 is the PREFERRED oil for the 5.0 L in a 1996 Ford Bronco )
I own A 1994 Ford Bronco Eddie Bauer with a 5.0 liter engine. The answer to your question is the oil capacity is exactly 6 quarts for an oil change.
Top center of engine at rear of block behind intake manifold.
6 Quarts of oil
6 quarts
6 quarts
6 qt
Front left side of the engine below the cylinder head in the engine block.
There are a variety of reasons from a bad sender or gauge to low oil level to worn bearings. Check the sender first as it's the easiest.