Help with a drain issue
 

Battery drain issue that is...I recently saved a 2004 A3 2.0TDi sport from being scrapped by my non mechanically minded brother to hopefully fix up and the first problem I want to address is a constant battery drain of around 1.7 amps (sometimes a little more) when everything is off. I do have a meter that measure DC amps.
I took out each fuse one at a time to try and narrow it down but no significant drop noticed so wondered if anyone else had similar and what was it?A scan showed an issue with the steering and convenience unit, I don't have the exact log at the moment, will have it scanned again soon to see what it showed exactly.It did have the usual problem with the micro switch in the boot catch but that has been resolved for a while.
Can anyone suggest what to take out of circuit to help find the battery drain or any other suggestions?Thank you.

Found what it was thanks to a mechanic friend of mine. The battery drain when the car is left unlocked is quite normal so me leaving it in the garage unlocked for over 3 days drained the battery. I put the meter on the battery and locked the car. within a minute the current drain went from 1.7 Amps to 500mA and would have dropped more I think but I unlocked the car again and it went back to 1.7 Amps.