Connected battery terminals wrong way round!
Yep, you read it right... I'm a dumb**s!
Replacing my battery on my A3 8P today.
The info leaflet that came with it said that if you want to avoid losing any settings (trip computer, stereo, etc) then hook up another battery via jump leads to the leads / terminals on my car - so that when I disconnect my leads from my old battery the car keeps getting current from the other battery (simples I thought).
So, I got my wife's car.
Clamped her positive terminal (I meant to clamp negative! I don't know what happened in my brain at that moment but anyway...) - and connected it to my negative. No sparks.... yet.
Then clamped her negative and connected to my positive. SPARKS for about 2-3 secs before I realised what I was doing and disconnected it.
Bear in mind the whole time my car's leads are still attached to the battery.
My car started okay with the new battery... No warning lights or anything.
But I'm paranoid to hell that I've probably frazzled or at least shortened the life of some circuitry that is likely to go pop at any moment.
I'm really annoyed at myself for being such an idiot.
Please tell me it's all probably going to be fine!?? :(