Electrical diagram of the model «250» with engine 123.026 (Mercedes-Benz E-Class W123)

Contents: Legend of the basic electrical…↡ Wire color designation ↡ Schematic diagram of electrical…↡ Schematic diagram of electrical…↡

Legend of the basic electrical circuit diagram of electrical equipment

№	Designation
1	Left headlight:
a	high beam thread
b	low beam thread
with	side/parking light lamp
d	fog light lamp
e	turn signal lamp
2	Brake Fluid Level Warning Light Sensor
3	Left front brake lining wear sensor
4	Gear Shift Lever Illumination Lamp*
5	Instrument cluster:
a	left turn signal indicator light
b	brake lining wear indicator light
with	brake fluid level and parking brake warning light
d	fuel reserve indicator light
e	fuel gauge
f	coolant temperature gauge
g	instrument lighting lamps
h	instrument lighting rheostat
i	low battery indicator light
j	high beam indicator lamp
k	right turn signal indicator lamp
l	electronic clock
6	Cigarette lighter with ashtray lamp
7	Radio*
8	Right headlight:
a	high beam thread
b	low beam thread
with	side/parking light lamp
d	fog light lamp
e	turn signal lamp
9	Automatic air damper heating coil
10	Idle Fuel Shut-Off Solenoid Valve II
11	Automatic antenna*
12	Parking brake indicator light switch
13	Coolant temperature sensor
14	Right front brake lining wear sensor
15	Front ceiling light with switch
16	Ceiling light switch in the left door pillar
17	Ceiling light switch in the right door pillar
18	Sound signal
19	Speed controller sensor*
20	Speed controller amplifier*
21	Throttle actuator*
22	4-way alarm switch/relay interrupter
23	Glove box light switch
24	Glove compartment light
25	Fuse box
26	Idle Fuel Shut-Off Solenoid Valve I
27	Relay I for switching on window lifters*
28	Relay II for switching on window lifters*
29	Door window switch*
30	Horn switch
31	Combined steering column switch:
a	turn signal switch
b	headlight signal switch
with	headlight switch
d	windshield washer switch
e	windshield wiper speed switch
I	intermittent operation
II	low speed
III	high speed
32	Speed control software switch:
A	off
V	slowdown/tuning
SP	return to previous speed of movement
IN	overclocking/tuning
33	Windshield wiper motor
34	Windscreen wiper intermittent relay
35	Ignition switch
36	Rotary light switch
37	Sunroof Electric Motor*
38	Electric sunroof switch*
39	Automatic Transmission Solenoid Valve*
40	Foot switch for low gear engagement*
41	Starter interlock and reversing light switch*
42	Air Conditioner Relay II*
43	Air Conditioner Relay I*
44	Fan switch with light
45	Brake light switch
46	Windshield washer pump
47	Left headlight wiper motor*
48	Right headlight wiper motor*
49	Headlight Washer Relay*
50	Headlight washer pump*
51	Distributor*
52	Spark plugs
53	Ignition coil
54	Lighting:
a	air flow direction knobs
b	heater control knobs
with	switch*
55	Thermoelectric switch (62°C) of the air conditioner dryer*
56	Thermoelectric switch (100°C)
57	Left rear door window lift motor*
58	Left rear door window switch*
59	Power window switch block*:
a	left rear door window switch*
b	safety switch
with	left front door window switch
d	right front door window switch
e	right rear door window switch
60	Fan motor
61	Additional resistance of the fan motor
62	Air conditioning temperature selector switch with lighting*
63a	Air conditioning compressor electromagnetic clutch*
63b	Air Conditioning Compressor Emergency Pressure Sensor* (switching on at 2.6 kgf/cm², switching off at 2.0 kgf/cm²)
64	Additional fan*
65	Additional fan relay*
66	Rear window defroster switch
67	Rear window heating time relay
68	Additional resistance 1.8 Ohm
69	Left front door window lift motor*
70	Right front door window lift motor*
71	Diagnostic connector
72	TDC sensor
73	Luggage compartment light
74	Wiring connector to rear vehicle consumers
75	Right rear door window switch*
76	Right rear door window lift motor*
77	Fuel level indicator sensor
78	Rear interior light
79	Ceiling light switch in left rear door pillar*
80	Rear Interior Light Switch*
81	Ceiling light switch in the right rear door pillar*
82	Generator with electronic voltage regulator
83	Battery
84	Starter
85	Right rear light:
a	turn signal lamp
b	red/parking light lamp
with	reversing light bulb
d	brake light bulb
86	Rear window heating element*
87	License plate light
88	Left rear light:
a	turn signal lamp
b	red/parking light lamp
with	reversing light bulb
d	brake light bulb
e	fog light lamp

* Depending on the configuration.

Wire color designation

Designation	Transcript
bl	blue
br	brown
el	ivory
ge	yellow
gn	green
gr	grey
nf	colorless
rs	pink
rt	red
sw	black
vi	violet
ws	white

The first two letters indicate the color of the wire, the second two letters indicate the color of the stripe on the wire. The numbers next to the color designation of the wire indicate its cross-section in mm².