Seat Altea XL 1.9 tdi: Sudden Dashboard and Cabin Power Loss While Driving

Hello.
Maybe someone has encountered such a problem in Seat Altea XL 1.9 tdi that I have and will help.
Sometimes while driving, the tension on the entire dashboard and the car cabin suddenly disappears. All the lights go off, the counter turns on the same with the tachometer, fuel and temperature gauge, and the display and the radio. The support also stops working. However, the daily mileage, the time is not deleted and the radio stays stored, the engine works all the time. It seems as if someone suddenly turned off and removed the key while driving, and in a second put it in and turned it. I checked all the fuses, ground connections, those I saw, unscrewed, cleaned, and replaced the ignition switch. I called car electricians in my area, unfortunately they said they did not know what it could be and they told me to drive until it turned off completely.
Maybe someone will suggest something because it becomes dangerous when suddenly everything disappears.
Thank you in advance for any help.

Probably cold February somewhere

Just where to look for them. Today it is a massacre with this meter on a distance of 20 km began to go crazy 10 times. He went to a mechanic's friend and we plugged the computer and it showed errors as in the attached photos. All managed to delete except one from the power steering.

Try to disassemble the counter, maybe something will show up

citromaniak wrote:

Try to disassemble the counter

Don't take anything apart, that's the way.
Please provide these errors.
I would rather look for relays or their control.

sk700 wrote:

citromaniak wrote:

Try to disassemble the counter

Don't take anything apart, that's the way.
Please provide these errors.
I would rather look for relays or their control.

I only have the data as in the attached photos. I will try to drive up again and check these errors. After reading the errors, it wrote - "temporary voltage loss" at each error.

A colleague writes well, at the beginning check the transmitters above the legs if they sit well in their places. I had the same thing in turtleneck V and it was the transmitter above my legs, but I don't remember which one, I know that this relay additionally had a PCB in the housing with a soldered bone. For ease of use, check the terminal supply relays. I have borrowed the link so to work
http://seat.auto.com.pl/forum/viewtopic.php?t=179272

They follow the relays, I started replacing them one by one and testing what would happen. I have already replaced the 5th turn and I drove the whole week without any problems, I did about 600 km and everything was fine until today, where after about an hour and a half of continuous driving the problem returned.
I was on the computer and there is an error with the terminal 30 supply voltage - he writes a sudden voltage loss error number 00668 and two more error in the alarm siren and shaft position sensor. However, these errors can be cleared. There is only one error 01309 power steering system controller and this error cannot be deleted.
I tried to remove the relays one by one with the ignition on to see if the same effect will appear as when driving (everything goes out) but nothing like that happened.
I don't know where to look anymore.

terminal 30 is a constant plus from the battery, you need to check the entire power lines, in what modules are these errors?

Sometimes you don't have one of your main fuses blown so you can't see it. I had such a case, the fact was not in a seat but it revealed itself over time or with a higher temporary power consumption.

Maybe you have a cold February on the meter somewhere at your ankles?

I am beginning to wonder if it is sometimes cold February somewhere in the meter. This morning I knocked while driving with everything I could and nothing, and in the afternoon when I came back from work, only the speedometer turned off and the indicators on the speedometer came on, the rest worked fine.

I had this in the Passat IV tdi, but in my car the pins in the plug powering the clocks were broken. After repairing, the problem was gone.

It is after Christmas that I check the meter, maybe something is wrong with me too.

Gentlemen, can cold February in the meter turn off the radio? I have already looked through everything I can, replaced all relays and I am inclined to the fact that my problem is cold February in the meter. I noticed that someone was already taking out the clocks because there is no one screw.

Subject solved. The reason was a poorly repaired alternator. The previous electrician put on some weird Chinese voltage regulator that went crazy at times and gave a voltage above 17V per installation which led to a computer reset. The topic can be closed.