Light update Audi C4 100 / A6 C4 // Audi 80/90 B4 81 85 4000

The retrofit kits are prefabricated and pre-wired components for converting the main headlights (low and high beam) to relay operation. The operating current to the headlights is then no longer switched via the steering column switch, but via the corresponding relay. Only the control current (approx. 150 mA) flows to the relays via the actual light switch, rather than the previous 10 A. This measure not only relieves the load on the light switch, but also prevents the 1-2.5 V voltage losses caused by contact wear. Due to these voltage losses, often only 9-11 V reach the lamps instead of the required 12-13 V, which reduces light output by up to 50%!

With relay control these losses are largely avoided!!!

The retrofit kits work on vehicles with or without a lamp control unit. The lamp monitoring function is not disabled!

The relays are therefore integrated between the steering column switch and the fuse box and thus in front of the LKG.

You only need one relay for the low beam and one for the high beam, since the distribution and protection of the two lamps (left/right) takes place after the relay in the fuse box.

The power supply (terminal 30) is supplied directly via the central electrical system using a 4mm² cable (red). Therefore, the relays do not require additional protection.

The installation is completed with little effort - even for the inexperienced enthusiast - within about 30 minutes.

Depending on the vehicle electrical system, power loss at the light switch, etc., the light output can almost double after the conversion!!! The voltage now applied to the bulbs is the battery voltage minus 0.5V. Typically, the relay circuit produces a voltage of 13-13.5V at the bulbs. A voltage loss of approximately 0.5V remains compared to the battery voltage. This is due, on the one hand, to the resistance caused by the cables, relays, and bulbs, and, on the other hand, to possible age-related corrosion at the ground connections, or the condition of the battery, etc. However, this type of power loss is always present and therefore completely normal. This type of "buffering" also prevents premature bulb wear, as can be seen in many current vehicles.

Custom-made - No returns / exchanges!

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