1. Can I buy your products directly from you?

Unfortunately it is not possible for private customers to buy directly from us. We supply exclusively distributors, OE manufacturers, and auto repair shops. However, our products are available from almost all dealers

2. When the trailer is connected to the car, the car indicator lights glow only very dim and the indicator flashes twice as fast as usual.

The power supply to the trailer indicator control is not connected. Connect the steady plus cable to an adequate power supply unit.

3. The trailer indicators glow only very dim although I connected them to steady plus.

Check the connection between the steady plus cable and the power supply unit. When you tap into the steady power supply of an electrical component of the towing vehicle (e.g. trunk or interior lighting), it is important that the cross-sectional area of the cable you tap in is large enough!

4. When I check the function of the trailer socket after installation both indicator lights flash simultaneously even though the indicator is not switched to hazard warning lights mode.

Maybe the wrong test equipment was used. You should not use test equipment with light emitting diodes to test the wiring harnesses. The test equipment needs to be fitted with load resistors or the trailer indicator control will not  be able to recognize the trailer.

5. Do I have to apply parametric control to my car before installing the wiring harnesses for an Audi A4 (B6) or Mercedes Benz C class (W203)?

No, the application of parametric control is not necessary with wiring harnesses.

6. What does Check-Control stand for?

Check-Control monitors the lighting devices. Depending on the car manufacturer and model, it monitors the bulbs of the brake lights, rear lights (and more) and notifies the driver of malfunctions by a visual symbol or text in the dashboard.