TRANSFORMER 4374049 - Caterpillar

Engine Shutdown Caused By Water Temperature Fault
Simplified schematicWhen the engine temperature becomes too high, the normally open water temperature switch WTS contacts (2 and 1) (line 43) close. This, in turn energizes the water temperature relay (WTR) (line 43) and water temperature fault light (WTL) (line 44). WTR contact (line 44) closes to latch in the relay WTR.The normally open WTR contact (line 53) closes to energize the engine failure relay (ENFR) (line 54). Normally closed (N.C.) contact ENFR (7 and 1) (line 56) opens to de-energize relay RR (line 56). The contact across RR (8 and 5) (line 14) opens to de-energize SR1. When SR1 is de-energized, its contacts (line 13) close allowing current to flow to the latching fuel solenoid (LFS) (line 13). When energized, the LFS unlatches from the fuel ON position and mechanically latches to the fuel OFF position. RR contacts (6 and 9) (line 17) open to prevent the starting motor magnetic (SMMS1) (line 17) from energizing. RR contacts (7 and 4) (line 20) open which stops the flow of current to the arming relay (AR) (line 20).
To prevent personal injury due to accidental starting of the engine, disconnect the batteries before doing maintenance or repair