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Mercedes E class w123 - 300D (1987) Fuse Box Diagram

avatar Jonathan Yarden Mar 25, 2021 · 5 min. read

In this article you will find a description of fuses and relays Mercedes-Benz, with photos of block diagrams and their locations. Highlighted the cigarette lighter fuse (as the most popular thing people look for).
Get tips on blown fuses, replacing a fuse, and more.

Marcedes S class w123 -fuse box diagram

Fuse Ampere rating [A] Circuit protected
1 16 Auxiliary fan
2 8 Clock, Turn signal/hazard lamps, Radio, Power seats, Warning system, Courtesy lamps, Illumination Cluster/Center Console
3 30 Rear defogger
4 8 Headlamps (High low beam)
5 8 Automatic Climate Control, Transmission kick-down, Stop lamps/Backup lamps, Auxiliary fan
6 8 Courtesy lamps, Ani-lock brake system, Stop lamps/Backup lamps, Cruise control, Warning system, Warning indicators
7 8 Horn, Rear defogger,  Turn signal/hazard lamps
8 16 Outside heated mirrors, Anti-theft alarm system
9 8 Lamps: Park/TailMarker/License
10 8 Fog lamps
11 8 Headlamp wiper/washer, Lamps: Park/TailMarker/License, Illumination instrument: cluster, central console
12 8 Headlamps (Left: Low beam)
13 8 Headlamps (Right: Low beam, indicator)
14 8 Headlamps (Left: High beam)
15 8 Central locking system, Anti-theft alarm system, Power seats, Courtesy lights, Truck lamps, Automatic Antenna
16 25 Blower control/ Not used
17 16 Headlamps/Fog lamps, Wiper/washer, Headlamps wiper/washer, Power windows, Power seats
18 8 Glove box lamp, Wiper/washer (washer jet heaters), Front cigar lighter, Radio
19 16 Sliding roof, Heated seats, Orthopedic seats
a 25 Power seats
b 25 Power seats
c 25 Power Windows
d 25 Power Windows


Relay code Relay use
A Exterior lamp Failure Monitoring Unit
B Combination Relay (Turn signal, hazard lamps, wiper/washer)
C High speed relay (auxiliary fan)
D Low speed relay (auxiliary fan)
E Air pump Clutch (Electronic engine control/air injection management) – gasoline engine only
F Headlamp washer relay (Headlamp Wiper/washer)
G Power seat diode (Power seats)
H Power seat relay
I Power window relay (power windows)
K Auxiliary fuse holder (Anti-theft alarm system)


WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.

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