312C, 315C, 318C, 319C, 320C, 321C, 322C, 325C, 330C and M325C Excavators and 325C MHPU and 330C MHPU Mobile Hydraulic Power Units Engine and Pump Control – V2 – General Information (Electrical System)



Illustration 1 g00776407

Block Diagram Of The Electrical Circuit For The 312C, 315C, and 318C

(1) Disconnect switch

(2) Batteries

(3) Power circuit

(4) Breaker for the alternator

(5) Main relay

(6) Fuse panel

(7) Low current circuit

(8) Radio

(9) Cigar lighter

(10) Starter control relay

(11) Starter switch

(12) Neutral start switch

(13) Cab heater

(14) Air conditioner

(15) Lights

(16) Windshield wiper

(17) Windshield washer

(18) Start/stop circuit

(19) Starter motor

(20) Starter relay

(21) Alternator

(22) Horn

(23) Controller

(24) Switch panel

(25) Governor actuator

(26) Heater control unit

(27) Air heater

(28) Charging circuit

(29) Timer relay

(30) Neutral start relay

(31) Heater relay

(32) Governor Actuator Control



Illustration 2 g00696077

Block Diagram Of The Electrical Circuit For The 319C, 320C and 321C

(1) Disconnect switch

(2) Batteries

(3) Power circuit

(4) Breaker for the alternator

(5) Main relay

(6) Fuse panel

(7) Low current circuit

(9) Cigar lighter

(10) Starter control relay

(11) Starter switch

(12) Neutral start switch

(13) Cab heater

(14) Air conditioner

(15) Lights

(16) Windshield wiper

(17) Windshield washer

(18) Start/stop circuit

(19) Starter motor

(20) Starter relay

(21) Alternator

(22) Horn

(23) Controller

(24) Switch panel

(25) Engine shutdown timer

(26) Heater control unit

(27) Air heater

(28) Charging circuit

(29) Timer relay

(30) Neutral start relay

(31) Heater relay



Illustration 3 g00776409

Block Diagram Of The Electrical Circuit For The 322C

(1) Disconnect switch

(2) Batteries

(3) Power circuit

(4) Breaker for the alternator

(5) Main relay

(6) Fuse panel

(7) Low current circuit

(9) Cigar lighter

(10) Starter control relay

(11) Starter switch

(12) Neutral start switch

(13) Cab heater

(14) Air conditioner

(15) Lights

(16) Windshield wiper

(17) Windshield washer

(18) Start/stop circuit

(19) Starter motor

(20) Starter relay

(21) Alternator

(22) Horn

(23) Controller

(24) Switch panel

(25) Engine coolant temperature switch

(26) Start aid solenoid

(27) Start aid switch

(28) Charging circuit

(29) Timer relay

(30) Neutral start relay

(31) Governor actuator

(32) Heater control unit

(36) Heater relay

(37) Air heater



Illustration 4 g00824450

Block Diagram Of The Electrical Circuit For The 325C

(1) Disconnect switch

(2) Batteries

(3) Alternator Circuit Breaker

(4) Power Circuit

(5) Main relay

(6) Fuse panel

(7) Low current circuit

(8) Switch Panel

(9) Radio

(10) Wiper

(11) Washer

(12) Light

(13) Cigar Lighter

(14) Cab Heater

(15) Air Conditioner

(16) Controller

(17) Horn

(18) Timer Relay

(19) Key Start Switch

(20) Neutral Start Relay

(21) Starter Relay

(22) Starter Motor

(23) Neutral Start Switch

(24) Start/stop Circuit

(25) Engine Controller

(26) Heater Relay

(27) Air heater

(28) Fuel Pump Relay

(29) Fuel Pump

(30) Charge Circuit

(31) Alternator



Illustration 5 g00838351

Block Diagram Of The Electrical Circuit For The 330C

(1) Disconnect switch

(2) Batteries

(3) Alternator Circuit Breaker

(4) Power Circuit

(5) Main relay

(6) Fuse panel

(7) Low current circuit

(8) Switch Panel

(9) Radio

(10) Wiper

(11) Washer

(12) Light

(13) Cigar Lighter

(14) Cab Heater

(15) Air Conditioner

(16) Controller

(17) Horn

(18) Timer Relay

(19) Key Start Switch

(20) Neutral Start Relay

(21) Starter Relay

(22) Starter Motor

(23) Neutral Start Switch

(24) Start/stop Circuit

(25) Engine Controller

(26) Heater Relay

(27) Air heater

(28) Fuel Pump Relay

(29) Fuel Pump

(30) Charge Circuit

(31) Alternator

(32) Emergency Stop Switch

The electrical system consists of the following circuits:

  • Power circuit

  • Start/stop circuit

  • Charging circuit

  • Low current circuit