Relay for Skoda Octavia 1U5

Hello everyone,

Can anyone explain the function of relay 3 in the Skoda Octavia 1U5?
In the wiring diagram (from "So wirds gemacht"), the relay is labeled "Amplifier for lighting," and its part number is 1U0 941 243 C.
It has 6 connection pins and consists of a circuit board with 3 silicon diodes and 3 low-power metal film resistors.
Its connections include 3 different positive terminals, 1 for the trunk light, 1 for the seat heater lamp, and 1 for the ventilation control lamp.

I cannot detect any amplification effect from the combination of components, nor do I see any purpose for these low current loads in general.

I would be very grateful for any explanatory notes.

Greetings.
Claus.

Hello,

The book series you mentioned already had issues with incorrect wiring diagrams in my Audi A3 8L... I suspect a translation error.

Using three diodes, it would be possible to create a simple, non-blocking "OR" functionality.

For example, a shared light turns on when any one of several switches is activated and provides power to one of the inputs, without simultaneously providing power to the remaining inputs.

Best regards, Rainer.

Thank you for this description. I will try to create a circuit diagram of the relay to verify this circuit configuration.
Greetings.
Claus.

Hi,
The term "Relais 3" probably isn't quite right. It likely refers to the relay in slot 3 of the relay carrier, which is actually labeled as "Amplifier for Lighting" in the RLF documentation. I suspect a translation error from Czech or English ("Controller" or "Control Unit").
Do you have a wiring diagram from Etzold, and if so, could the relevant part be sketched out for discussion here?
And - curiosity - what's the problem behind it?
hg
Herbert.

This relay is used for various purposes within the Volkswagen Group, and essentially it only serves to switch voltages on and off.

I mentioned that I wanted to create a circuit diagram for the relay. Unfortunately, it took a bit longer than expected.
The terminals of the relay are not labeled, so I couldn't include any labels in the diagram. I took the "3 Plus" input labels from Etzold's diagram. I already described the outputs in my first post.
Looking at the circuit, I would associate the 1N5406 component with the power consumption of the trunk light.
However, the function of all the components is completely incomprehensible to me, and I wonder why the outputs weren't simply connected directly to the positive terminal. What is the purpose of the diodes?

The question was about the reason for my inquiry: The trunk light stopped working in hot weather. When it gets cooler in the evening, it works again. And no, the microswitch in the tailgate lock is fine; the problem is actually a lack of power reaching the lamp.

Greetings.
Claus.

The diodes prevent current from flowing in reverse.

To be more precise, above 58, the two control lamps receive a small amount of current (dimmed) through the resistors when the light is on, while above 58b, the current flows through the instrument lighting regulator. Of course, you wouldn't want to short-circuit these two sources. It would also make sense to use the 15 with a fuse instead of the 58.
I don't know why the trunk light is going through the diode. Perhaps the common ground point in the rear is playing a role.
hg
Herbert.

Thank you for the information; I learned something new.

Greetings.
Claus.