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Automotive component pin assignments according to DIN 72552

Yes, it's perfectly true. All those little numbers barely perceptibly cast in the bases of automotive relays are standardized by DIN 72552! Who knows - the following list may be helpful in emergencies, although it may not be complete or entirely correct:

Ignition and current supply
1Coil, distributor - low voltage
1aTo contact breaker I (distributor with 2 separate circuits)
1bTo contact breaker II (distributor with 2 separate circuits)
2Shorting circuit - magneto ignition
4Coil, distributor - high voltage
4aFrom coil I (distributor with 2 separate circuits)
4bFrom coil II (distributor with 2 separate circuits)
7Ballast resistor terminal to/from distributor
15Switched + downstream of battery (output of ignition/driving switch)
15aOutput at ballast resistor to coil and starter
17Glow plug and starter switch - Start
19Glow plug and starter switch - Preheat
30Input from battery +, direct 12/24 V series-parallel battery switch
30aInput from + terminal of battery II
31Battery negative terminal, or chassis ground, direct
31a Return line to battery II, negative (12/24 V series-parallel battery switch)
31bReturn line to battery negative terminal, or ground via switch or relay (switched negative)
31cReturn line to battery I, negative (12/24 V series-parallel battery switch)
33Main terminal connection
33aSelf-parking switch-off
33bShunt field
33fFor 2nd low-speed range
33gFor 3rd low-speed range
33hFor 4th low-speed range
45Separate starter relay, output; starter, input (main current)
Two-starter parallel operation - Starting relay for engagement current
45aOutput, starter I, Input, starters I and II
45bOutput, starter II
48Terminal on starter & on repeating relay for monitoring starting procedure
Turn-signal flashers (pulse generators)
49bOutput, 2nd circuit
49cOutput, 3rd circuit
Starter control
50Starter control (direct)
50aSeries-parallel battery switch - Output for starter control
with parallel operation of two starters with sequential control
50bStarting relay for sequential control of the engagement current
during parallel operation of two starters
50cInput at starting relay for starter I
50dInput at starting relay for starter II
50eStart-locking relay Input
50fStart-locking relay Output
50gStart-repeating relay Input
50hStart-repeating relay Output
51DC voltage at rectifier
51eDC voltage at rectifier with choke coil for daytime driving
Trailer signals
52Additional signals from trailer to vehicle
Wiper motors
53Wiper motor, input (+)
53aWiper (+), self-parking switch-off
53bWiper (shunt winding)
53cElectric windshield-washer pump
53eWiper (brake winding)
53IWiper motor with permanent magnet and 3rd brush
(for higher speed)
Trailer signals (see also 52)
54Trailer plug connections and lighting combinations, brake light
54gPneumatic valve for continuous brake in trailer, solenoid-operated
55Fog lamp
56aHigh beam, high-beam indicator lamp
56bLow beam
57aParking lamp
57LParking lamp, left
57RParking lamp, right
58Side-marker, tail, numberplate and instrument panel lamps
58bTaillight changeover for two-wheeled tractors
58cTrailer plug and receptacle assembly for single-conductor tailight with fuse in trailer
58dVariable intensity instrument panel light, tail light and side marker.
58LNumberplate lamp, left
58RNumberplate lamp, right
Alternators and voltage regulators
59A/c voltage output, rectifier input
59aCharging armature, output
59bTail light armature, output
59cBrake light armature, output
61Alternator charge-indicator lamp
B+Battery +
B-Battery -
D+Dynamo +
D-Dynamo -
DFDynamo field
DF1Dynamo field 1
DF2Dynamo field 2
U,V,WThree-phase alternator terminals
Multi-tone horn and emergency lights
71aOutput to horns 1 & 2 low
71bOutput to horns 1 & 2 high
72Alarm switch - revolving emergency light
Radio, cigarette lighter
75Radio, cigar lighter
77Door valve control
Normally closed and changeover switches
81aOutput 1, NC side
81bOutput 2, NC side
Normally open switches
82aOutput 1
82bOutput 2
82zInput 1
82yInput 2
Multi-position switches
83aOutput, position 1
83bOutput, position 2
83LOutput, left-hand position
83ROutput, right-hand position
Current relays
84Input, actuator and relay contact
84aOutput, actuator
84aOutput, relay contact
Switching relays
85Output, actuator (end of winding to ground or negative)
86Input, actuator (start of winding)
86aStart of winding or 1st winding
86bWinding tap or 2nd winding
Relays - N/C and changeover
87aOutput 1(NC side)
87bOutput 2
87cOutput 3
87zInput 1
87yInput 2
87xInput 3
Relays - N/O and changeover
88aOutput 1
88bOutput 2
88cOutput 3
88zInput 1
88yInput 2
88xInput 3
Directional signals
CIndicator lamp 1
C2Indicator lamp 2
C0Main connection for separate indicator circuits
worked by turn signal switch
C3Indicator lamp 3 (e.g., when towing two trailers)
LTurn-signal lamps, left
RTurn-signal lamps, right

Contact Phil Payne via the Kerbside Motors Home Page