Here is the wiring for early chrome bumper models.
This is an early C101 plug. Later model chrome bumper models had a round plug but the wires are almost all the same.
1 (Blue) = Alternator Charge Indicator
4 (Brown/Violet) = Temp Gauge
6 (Green/Yellow) = Idle Speed Control
7 (Violet/Red) = Fuel Pump Relay
8 (Black/Yellow) = Ignition/Starter
9 (Black) = Tacho (on early instruments clusters without econo gauge)
10 (Green) = Coil positive
15 (Blue/White) = Oil Level to Check Control
16 (Brown/Green) = Oil Pressure Gauge
17 (White/Blue) = Service Interval Lights
The connections for the M30 engine plug are:
E30 8 (Bl/Yl) connects to M30 18 (Bl/Yl) = ign/starter
E30 10 (Gn) connects to M30 7 (Gn) = Coil positive 15
E30 7 (Vi/Rd) connects to M30 13 (Gn/Vi) = fuel pump relay
E30 1 (Bu) connects to M30 1 (Bu) = Alternator Charge
E30 4 (Br/Vi) connects to M30 4 (Br/Vi) = Temp gauge
E30 16 (Br/Gn) connects to M30 5 (Br/Gn) = Oil pressure
E30 17 (Wh/Bu) connects to M30 11 (Wh/Gn) = Service Interval lights
E30 9 (Bl) connects to M30 9 (Bl) = early tacho with no econo gauge