connected battery terminals wrong by accident
 

Hi to all , unfortunately as i was wrapping up a DSG fluid change , Putting everything back together , I made a really stupid mistake by accident. I put the battery back on & accidentally connected the battery terminals in reverse. No huge sparks just the headlights came on & the horn came on. I immediately disconnected the battery & connected it the correct way.

Now here's the problem. I have no power steering the abs & tcs lights are on & the battery light is on. The alternator is not charging the battery , i cant unlock the trunk hatch & the ac compressor doesn't turn on but the fans will blow. I dont know what to do. The only things I've changed so far were all the fuses except relays. Any one have any ideas what could be wrong ? the car starts no problem everything else works except what I stated.

Outch!

The problem with reversing the positive and negative terminals is that you never know what damage it will do. Most of the time it will kill fuses/diodes on the alternator. So that is one thing I would plan on rebuilding or replacing first.
Next I would inspect the wiring harness from the alternator to the battery and the big wiring harness. It is very likely you might have fried a wire or multiple that you will have to replace before things start working again.

Run a Scan on your car, clear, start the car and let it run a bit - then scan the car again. Remaining codes are probably valid and will give you indications of what to trace down.
Hopefully you are only looking at wires or some fuse you missed. I would hate to think the ECU got fried or some other critical component that cost thousands.

Sorry for the late update . Car was repaired by the audi delearship. Alternator was fried . After they replaced that everything else work properly again. Cost me $413.00

Glad it was just the Alternator. Luckily you also decided not to replace it yourself as that is one PITA to get in and out - but could have easily saved you 200 bucks.

BTW the EPS /steering light is always on after you remove the battery power (learned the hard way). Once you start driving it will turn off if nothing is broken. It will however not turn off until you drive!