NickJA

Hi all,
In hot temperature (36+ Celsius) the electrics in the car, lights, display, indicators, speedo, etc etc shuts off.
the car will beep a few times and everything is black.
the only thing I can do is turn the car off and on. Usually it will happen again within a couple minutes - obviously making it pretty dangerous to drive without indicators and possibly even without breaklights - but I can’t confirm the breaklights.


ive tried to attach a video but I’m not sure if it has worked.

thanks

gk1

The video did not work.
Where are you located?
What is your battery age?
Cold weather may be hard on a battery but hot weather kills batteries.

NickJA

thanks for your reply.
I live in Sydney Australia.
my battery is almost 1 year old, it happened initially 2 or so years ago.. and basically every summer since at random. Never in the winter.

thanks

gk1

Did you have someone scan it for any fault codes?

Nick Everill

Did you ever find an answer to this? I’m having the same issue.

NickJA

hey mate, Yes I did.

Audi states they checked and found a fault in the alternator was creating high voltage faults in various control units which was causing the electronics to cut out.
they replaced the alternator under warranty and I haven’t had an issue since.

they also found another error with the ECG unit and swapped that out under warranty but it wasn’t related to the main issue.

hope this helps!!

Nick Everill

We have very different models but I’ll look into this. Hopefully that’s all it is. Thank you!

Sarp Daltaban

Hi, I have the same problem but even worse. My car shuts down gradually, I mean the engine stops at the end. Then I enter a shadow and wait for 30 mins to get another cooldown for the electricity.

If the car is under the sun 36C°, when I start the engine, front panel, AC, lights and engine stops gradually after a while. I feel lucky to see this issue on the web. But what about voltage regulator? Is the alternator only responsible or what was the defect on it? How did they diagnosed it?

Kind Regards

silver_tt

The voltage regulator is part of the alternator. While you can replace just the voltage regulator and put the same alternator back in I would not try to based on past experience unless you don't mind trial and error. On my track car I had a similar issue -- only happened when it was really hot like 35+ C. I could see the voltage swing wildly sometimes when I had the issue so I was sure it was the voltage regulator and replaced just it for $30 (lots of these German cars use the exact same voltage regulator) instead of the whole alternator for a lot more on that car. Anyway it helped the issue a lot but actually made the problem more difficult to diagnose; because it ended up actually being other parts of the alternator that were failing but only in the heat and only at very specific RPM ranges -- it was so bizarre. It even passed a cheap bench test but didn't fail until the alternator was taken out of the car and tested with more sophisticated equipment. In the future I will just say screw it and replace the whole alternator, it's not worth my time with trial and error, maybe others feel differently.

This issue you are describing can almost for sure be explained by either the battery, the alternator, or one of the wiring harnesses. Recall that resistance builds as heat increases.......

Sarp Daltaban

Thanks for the quick reply. My car is audi tt mk2. I will start with battery replacement, then the alternator but, where exactly the wiring harnesses are or is there a way to check them properly? You mentioned restistance also, so should I check the BCU? May be deeper than that?