Sending Units and Switches

Figure 1-16. Late crankcase breather and fire extinguisher system.

1-23. Sending Units and Switches

the current is transmitted to the electrical oil

gage on the vehicle instrument panel.

a. Oil Pressure Sending Unit (fig. 1-1). The

b. Low Oil Pressure Warning Light Switch.

electrical oil pressure gage sending unit on early

The low oil pressure warning light switch is

engines was located at the right rear of the right

furnished with the engine and it is located at the

side of the crankcase in the main oil gallery line.

right rear of the right side of the engine crank-

On late engines, for ease of maintenance, the

sending unit is relocated to the front of the

case in the main oil gallery line near No. 5 right

cylinder. The electrical contact points in this

crankcase at the opening in the gallery line at

No. 1 right cylinder. This sealed sending unit

switch close when the oil pressure in the main oil

consists of a threaded plate to which a

gallery falls to 1132 psi. The completion of the

electrical circuit lights the low pressure warning

diaphragm, a radially notched spring, and an

lamp on the vehicle instrument panel.

o v e r l o a d guard plate are crimped. Electrical

c. Oil Temperature Sending Unit (figs. 1-1).

resistance in the sending unit varies directly as

The oil temperature sending unit is located at the

the oil pressure varies. The resulting variation in

1-21