no start, no lights on in dashbord, no power on OBD

[Bosho13]

Hello

       First I want say everybody I am new on this forum and I don't know if my topic will be validate ( because of new) but this is what was happened:

I have a 2008 Audi A6, last year in August I did something stupid, I gave it power and reversed the terminals, I burned the alternator, I changed 4 fuses for the MMI, and more, after which it started, something star drain my battery (bought new in May 2024), last week I tried to find the consumer by removing all the fuses one by one to see which consumer I have, before I put a meter and it shows around 3.44 amps, all the fuses are ok, I took pictures before I took them out to know where I need to put them back, after which I also removed the positive terminal to measure there too, I don't know what gave me the positive terminal, the important thing is that now comes the beautiful part: it doesn't start anymore (I put the key in and I turn to start , is doing like vruuum 2 sec and that's it the engine stop) the dashboard clocks don't turn on anymore, there is no power to the OBD socket so I can put VCDS on it. If anyone have a clue about my problem please let me know asap.

Thank you

[cliffcoggin]

Dumitru.

Considering the potential for damage to delicate electronics by reversing the polarity it will be a miracle if the car can be restored without help from an auto electrician.

[Bosho13]

how I said, after reversing polarity I change the alternator and I was luky and I change 4 or 5 fuses for MMI and something else , but afer that the car was start and drive very good, like before. My problem is now with this no start , no lights on dashbord and no power for OBD. Maybe with someone was in this problem.