Ok, this is the explanation to the 1973 wiring diagram.  The text in the diagrams was in Danish, so I have translated the keys here.

Key - description - current track

A- Battery; 9
B- Starter; 10,11
C- Generator; 1,2,3
C1- Voltage Relay; 1,2,3
D- Ign. Switch; 11,12,19,37
E- Wiper switch; 16,17
E1- Light switch; 22,24,26,27
E2- Dip switch; 21,53,54
E3- Hazard switch; 51,52,53,54,57,58
E9- Fresh air fan switch; 19,20
E15- Heated rear window switch; 18
E24- Switch for seat belt with connector, left; 39
E25- Switch for seat belt with connector, right; 38
E26- contact strip in passenger seat; 38
F- Brake light switch; 42,43,44,45
F1- Oil pressure switch; 47
F2- Door switch, front left, with switch for buzzer H5; 36,37
F3- Door switch, front right; 34
F4- Reversing light switch; 63
F5- Switch for luggage comp. light; 28
F15- Tranny switch for the safety belt's warning system; 40
G- Fuel tank sender
G1- Fuel gauge
G4- Ignition time sender; 61
G6- To the electric fuel pump; 4
H- Horn pressure switch; 41
H1- Horn; 41
H5- Ignition switch buzzer; 35,37
H6- Switch in ignition switch for buzzer H5; 37
J- Dip relay; 21,23
J2- Hazard blinker relay; 51
J9- Relay for heated rear window; 13,18
J16- Relay for injection system; 7,8
J17- Fuel pump relay
J21- To the injection electronic control unit; 5,6,8
K1- High beam warning lamp; 22
K2- Charging system warning lamp; 46
K3- Oil pressure warning lamp; 47
K4- Parking light warning lamp; 26
K5- Turn signal warning lamp; 49,50
K6- Hazard blinker warning lamp; 58
K7- Dual circuit brake warning lamp; 43,45
K19- Safety belt system warning lamp; 38,39,40
L1- Sealed beam unit, left; 21
L2- Sealed beam unit, right; 23
L6- Bulb for speedometer light; 25
L8- Bulb for clock; 25
L10- Bulb for fuel gauge; 25
M2- Bulb for tail- and stoplight, right; 30,44
M4- Bulb for tail- and stoplight, left; 27,42
M5- Bulb for turn signal and parking light, front left; 31,53
M6- Bulb for turn signal, rear left; 52
M7- Bulb for turn signal and parking light, front right; 32,54
M8- Bulb for turn signal, rear right; 55
M11- Bulb for side marker, front; 31,32
M16- Bulb for reversing light, left; 63
M17- Bulb for reversing light, right; 64
N- Ignition coil; 62
O- Distributor; 60,62
P- Spark plug connectors; 61,62
Q Spark plugs; 61,62
S1 to S12- Fuses in the fuse box
S13- Single fuse for the reversing lights (8A); 63
S14- Single fuse for the heated rear window (8A); 13
T- Wire adapter
    b- in the engine compartment
    c- under the rear seat
T1- Wire connector
    a- under the rear seat
    b- under the instrument panel
    c- left side in engine compartment
T2- Wire connector, 2 way
    a- in the rear luggage hatch
    b- under the instrument panel
    c- left side in engine compartment
    d- behind zipper in the passenger seat
T3- Wire connector, 3 way
    a- in the left headlight bucket
    b- in the right headlight bucket
    c- in the front luggage compartment, left side
T7- Connector, 2 way, on the inner seat track on the passenger seat
T20- Diagnostic central connector; 59
V- Wiper motor; 14,17
V2- Fresh air blower fan motor, front; 19
W- Interior light; 34
W3- Luggage compartment light; 28
X- License plate light; 29
Y- Clock; 33
Z1- Heated rear window; 13
(1)- Ground cable from battery to frame; 9
(2)- Ground cable from transmission to frame; 1
(4)- Ground cable over steering coupler; 41
(10)- Ground point, instrument panel; 14,19,36,59
(11)- Ground point, speedometer; 21,33,44
(12)- Ground point, fuel gauge; 58
(13)- Ground point, clock; 46

See the wiring diagram for wire gauge in mm2.

PerL
73 Variant L