Rules for handling electrical circuits
If you need to find a malfunction in the electrical system or install additional electrical equipment, you can not do without a diagram depicting the flow of current and cable connections. The corresponding current circuit must be closed without fail, otherwise the current will not flow. For example, it is not enough when voltage is applied to the positive terminal of the headlight, and the circuit on the ground contact is not closed.
Therefore, the battery ground cable is connected to the body. However, this earth connection is not sufficient, and the corresponding consumer has a direct earth wire, whose insulation is usually black. Switches, relays, fuses, measuring devices, electric motors or other electrical elements can be built into separate current circuits. In order to be able to connect these devices correctly, the individual cables have different colors.
Cable colors
The letters on the individual conductors indicate the color of the cable:
- 1 - symbol (example)
- 2 - single color cable
- 3 - black
- 4 - cable with stripes
- 5 - white (cable color)
- 6 - red (stripe color)
Single letters indicate a single color cable.
Example: B is black. For two-color cables, the first letter indicates the main color of the cable, the second letter indicates the color of the strip.
Example: W/R indicates a white cable with a red stripe. The adjacent letter in brackets identifies the corresponding cable harness.
Example: (F) - front cable harness in the instrument panel and in the right engine compartment.
Cable color codes
| Code | Color |
| L | blue |
| B | black |
| BR | brown |
| DL | Navy blue |
| DG | dark green |
| G | green |
| GY | grey |
| LB | light gray |
| LG | light green |
| N | beige |
| O | orange |
| P | pink |
| R | red |
| PU | purple |
| T | beige |
| W | white |
| Y | yellow |
| V | violet |
Plug symbols
Plugs and sockets are indicated in the diagram as follows:
Identical plugs are connected in the diagram by a dashed line. The plug without color designation is colorless or white. Slots that are not in use are marked with an asterisk (*).
Mass connections
Ground connections in the diagram are usually at the bottom.
If the ground connection is by cable, the ground point is indicated by a number. If the earth connection is carried out directly through the body, this is indicated in the diagram by a filled dot.
Abbreviations on diagrams
| A | amps |
| ABS | anti-lock system |
| ACC | optional equipment |
| A/C | air conditioner |
| A/T | Automatic transmission |
| ALT | generator |
| B | battery |
| B/L | top/leg compartment |
| CPU | electronic control device |
| CCT | switching circuit |
| COMBI | combi |
| DEF | defroster |
| DIESEL | diesel engine vehicles |
| ECU | engine control device |
| EGI | electronic injection system |
| EGR | exhaust gas return |
| ELEC | electric |
| F | front |
| FL | front left |
| FR | front right |
| F/B | control |
| F/I | injection valve |
| GEN | generator |
| H/D | heater/defrost |
| HEAT | heater |
| HI | high beam |
| IG | ignition |
| ILLUMI | lighting |
| INT | interval drive |
| J/B | fuse box |
| LH | left |
| LO | dipped beam |
| M/T | Manual Transmission |
| NC | normally closed (contactor) |
| NO | normally open (circuit breaker) |
| OFF | switched off |
| ON | included |
| P/S | servo control |
| R | behind |
| RH | on right |
| RL | rear left |
| RPM | rpm = revolutions per minute |
| RR | rear right |
| SQ | square millimeters |
| SW | switch |
| TEMP | temperature |
| V | volts |
| VOL | volumes |
| W | watts |