The vehicle's electrical system is single-wire, with a nominal voltage of 12 V; the negative terminals of the current sources are connected to the body ("vehicle ground")
The electrical equipment diagram of the ZIL - 131 is shown in Fig. 1.
ZIL-131 electrical equipment diagram: 1 - sidelight; 2 - headlight; 3 - five-terminal wiring panel; 4 - four-terminal wiring panel; 5 - spark plugs; 6 - generator; 7 - high-voltage wires; 8 - Low voltage wire from ignition coil to distributor; 9 - ignition coil; 10 - ignition distributor; 11 - underhood lamp; 12 - emergency oil pressure drop lamp; 13 - capacitor filter; 14 - relay-regulator; 15 - radio interference filter; 16 - radio power socket; 17 - buzzer-signaling device; 18 heater electric motor; 19 - brake light switch; 20 - heater capacitor; 21 - cabin light; 22 - cabin light switch; 23 - cabin fan electric motor; 24 - front axle switch; 25 - push-button switch for rotary spotlight; 26 - rotary spotlight switch; 27 - heater electric motor switch; 28 - cabin fan switch; 29 - fuel level indicator sensor switch; 30 - ceiling light switch and cabin lights; 31 - central light switch; 32 - electromagnet relay 33 - front axle engagement indicator lamp; 34 - high beam indicator lamp; 35 - pressure gauge (two-needle) for monitoring air pressure in the pneumatic brake drive system; 36 - oil pressure indicator; 37 - instrument lighting lamps; 38 - signal contact device; 39 - fluid temperature gauge; 40 - ammeter; 41 - 20 A vibration fuse; 42 - fuel level gauge; 43 - block of two 6 A bimetallic fuses; 44 - direction indicator lamp; 45 - direction indicator interrupter; 46 speedometer; 47 coolant emergency overheating indicator lamp; 48 - tire air pressure gauge; 49 - combined ignition and starter switch; 50 - foot switch for headlights; 51 - front axle switch; 52 - electromagnet of the front axle air valve drive; 53 - turn signal switch; 54 - horn button; 55 - portable lamp socket; 56 - cab light; 67 - fuel gauge sensor; 58 - tail light; 59 - portable lamp socket (located on the frame); 60 - portable lamp socket (located on the platform); 61 - portable lamp; 62 - trailer socket; 63 - push-button switch for the horn; 64 - battery switch; 65 - battery; 66 - swivel spotlight with handle; 67 - additional ignition coil resistor; 68 - radio interference filter in the ignition coil circuit; 69 - starter relay; 70 - coolant temperature gauge sensor; 71 - starter; 72 - coolant overheating warning lamp sensor; 73 - sound signal
