LOCK 6K0079 - Caterpillar

ECS In AUTO Position
IC Closed
Simplified schematicWhen engine control switch (ECS) is in the auto position, ECS contacts (9 and 10) (lines 56 and 57) are also closed. When initiating contact (IC) (line 59) is closed, the run relay (RR) (line 56) energizes. This causes RR contacts (8 and 5) (line 14), RR (6 and 9) (line 17) and RR (7 and 4) (line 20) to close.RR (8 and 5) (line 14) - Normally open (N.O.) contact across RR (8 and 5) closes to energize the slave relay #1 (SR1) (line 14). SR1 contacts (line 13) open.RR (6 and 9) (line 17) - Normally open (N.O.) contact across RR (6 and 9) closes to energize the starting motor magnetic switch (SMMS1) (line 17). When SMMS1 closes its contact (line 6) current is sent in two directions. Current actuates the solenoid (LFS) (line 7) which is then mechanically latched in the fuel ON position. Current also energizes pinion solenoid #1 (PS1) (line 6) which in turn closes its contact (line 5) to energize the starting motor #1 (SM1) (line 5). Also, the overcrank timer (OCT) (line 21) starts its timer. After the engine cranks for approximately 30 seconds without the engine starting, OCT will energize the overcrank fault relay (OCR) (line 35).RR (7 and 4) (line 20) - Normally open (N.O.) contact across RR (7 and 4) closes. This connects the engine speed switch (terminal 10) to the arming delay timer (ADT) (terminal 1). When the engine reaches 400 rpm the ADT will energize.Once the engine has started and reached approximately 400 rpm:The engine speed switch's (ESS) crank termination (CT) (contacts 11 and 10) (line 20) close. This energizes the ADT (line 20) which has a 10 second delay. The delay allows time for initial oil pressure to build-up causing the oil pressure switch (OPS) (line 39) to open at 93.0 21 kPa (13.5 3.5 psi). This prevents the oil pressure fault relay (OPR) (line 39) and light (OPL) (line 40) from energizing on normal start-up and shutdown.As the engine starts and ESS senses a speed of 400 rpm through the magnetic speed pickup (MPU) (line 62), the ESS opens the starting motor and latching fuel solenoid circuit by opening the crank termination switch contact across ESS (CT) (11 and 12) (line 17).
Simplified SchematicWhen engine control switch (ECS) is in the auto position, ECS contacts (5 and 6) (line 36) are also closed. This provides a path to latch in one of the fault relays (OCR, OPR, WTR or OSR) should a fault occur.IC Open
If the engine is running with the ECS in the auto position, ECS contacts (9 and 10) (lines 56 and 57) and initiating contact (IC) (line 59) are closed. When the IC opens, run relay (RR) (line 56) de-energizes. This opens RR contacts (8 and 5) (line 14) which stops current from flowing to the slave relay (SR1). When SR1 is de-energized, its contacts (line 13) close allowing current to flow to the latching