Terminal 75 relay and 75x fuses not powered

[SirPete83]

Hi there,
I want to reactivate this post again. I have a Polo 6R and the ventilation has recently stopped working.
I found out that Terminal 75 is dead.
I tested the type 100 relay.
Fuses 40, 41 and 42 have no voltage, not even when the ignition is activated.

Has anyone already had this problem?

Maybe someone can provide the full wirering diagram?

Thanks.

[iichel]

did you check the output of the ignition lock to the relay?

[SirPete83]

Hallo, not for the moment will check it. Are you sure there is a direkt connection between the relay and the lock? I meassuerd 12 V at the source terminal of the relay that will be switched to Terminal 75x, when i turn the key to ignition so I can feel the relay switches.

In my opinion the relay will be switched off during motor start. and again switched back on, if motor is running. could ne a switching behavioir of the key lock right?

How to remove the case under the stearingwheel, where fuse box is attached?

[iichel]

If the relay indeed clicks then that's fine. Then I guess the relay is broken, since it does click and it does have source voltage.

[SirPete83]

I checked the Relay on the desk it works fine. I will do some more diagnostics and provide my results.

[SirPete83]

I did some tests again today.

1. Relay removed and bridged. Rear wiper works! 12 V socket too. However, the fan turns very slowly, which makes me wonder ... that could be the trigger. I stupidly didn't start the engine. But actually it shouldn't change anything.

2. I extended the switching lines from the relay. Relay does not switch! Measuring is better. Voltage is 0 V Ground is available! +12 missing is not switched to the relay.

I assume that a module does not have enough voltage and does not activate the relay and the ventilation therefore only allows a low speed.

Oh, there is a digital climate control installed, so not these 4 manual levels but an automatic one.

I have no more ideas and checked all the backups again. Measure the fuses with the ignition switched on.

[iichel]

So is the relay not operated or is the relay not clicking when it should?

[SirPete83]

No it does not click at all.
It is operation when I test it with an external power source. but not in the car

[iichel]

So does it receive a signal on the thin red/black wire?

[SirPete83]

Hi,
the coil has ground the other wire is death.
static 12V at one contact is present.
Peter

[SirPete83]

Hi Michael,
becaus I am a new member here I cannot sent a direct message to you.
Do you have the electronic documentation of this car?
Best regards Peter

[iichel]

[SirPete83]

Ok Thanks. I think this should be helpful. But the red line is not connected to the starter right? The 1.5 wire between the key switch and the relay is it direct connection, or is something else drivien by this contact?
I ask because of the behavior of the low speed, while I short the Relay to simulate the relay is closed. so the missing Voltage activates other parts?

To check the whole function I have to provide 12 V to A33 and 75x. Than hopefully the fan runs on the selected speed.

[iichel]

It's a direct wire from ignition lock pin 6 to the relay. Either the ignition lock is not giving 12V or the wire is somehow broken. Measure at the relay for 12V (but you did, you didn't have it). Now measure the output of the ignition lock pin 6. If it is giving you 12V, make a new wire to the relay since the current wire is broken. Or the ignition lock is not giving 12V, then that is broken and you need to resolve that.

[SirPete83]

Ok, but again. the fan was only on low speed even I selected highest speed on the controlpannel.
Is the Pin 6 of ignition lock sourcing anything else?

Yesterday I tried to remove the cover under the steeringwheel, removing the three screws and the gasket around the key lock, but it was not able to remove the cover.