Imagine you would like to mount additional headlights. There is a switch already, in this case with indicator light. (small light in the wiring diagram) A few questions should be dealt with before you start:- When may these additional headlights be switched on?- How are these headlights fused?- Do you want to equip the circuit with or without power relay?
When or if the additional headlights may be switched on, depends, e.g., also on where they are mounted. Fog lamps which are mounted less than 40 cm from the edge of the vehicle can be coupled to the parking lights (wiring diagram 1 and 2). If they are mounted further to the center, they may operate only with dipped headlights (wiring diagram 3 and 4). If the cross section in the switch is sufficient, the power relay is obsolete (wiring diagram 1 and 3). If however, you have the possibility to mount the power relay in a waterproof position in the engine compartment nearby the additional headlights, this is, particularly in the case of long wiring to the interior, the more elegant solution (wiring diagram 2 and 4). The circuit above is based on a customary, simply switched lighting system. The main light switch should be at the top, and the dipped headlights/high beam-switch directly below it. This part is common to all wiring diagrams, because it already exists in the vehicle. Even if the layout differs, somewhere there must be a cable which carries current to the parking lights (wiring diagram 1 and 2) or to the dipped headlights (wiring diagram 3 and 4). If the fusing of this cable is not obvious, you should favour the power relay circuit (wiring diagram 2 and 4). The section outlined in red indicates a possible switch with integrated pilot light. There remain three outward connections. If no wiring diagram exists, you can only try it out. If you put power to the correct two poles of an automatically fused 12V-power pack (under no circumstances the vehicle battery), the light must burn when the switch is operated. There is however, one connection possibility, with which a short circuit is created, therefore, it is wise to use a special power pack. 07/08