I am picking up 2016 mini countryman s only 67.5k miles this Wednesday and car doesn't crank and start. the owner says it's been sitting for 1.3 years since it doesn't start. I checked the car and it clicks and could hear starter kicks in but not cranking at all. The owner replaced the battery a few weeks ago. I'm planning to start from replacing the ground strap but I wonder if I could use 4 ga ground strap from autozone (pic bottom) instead of oem part since the dealership is about 40 mins away from my place and costs about $70 and they said it might take a week to get it. it says 4ga ground strap 13 inch length. if there is any other option, please let me know. I used AUTEL AP200 (bluetooth scanner) to scan the car and those error codes popped up and while I was scanning, I noticed that the battery symbol kept showing on the dash. I tried to start up more than like 5 times so I could hear if starter kicks in, is that why battery was dead or something? anyway I checked the error codes and found that CAS system had no problem (so glad that it was not the problem, It seems like pita). upon checking error codes, what do you guys think about what problem will be? I would be happy to get any advises.

 

I would pull the spark plugs, remove the belt, get a socket on the crank bolt and see if you can turn it over.
Since its been sitting so long I'd lubricate the cylinders.
Alot of the errors are probably due to it being without battery power for so long.
What kind of battery, AGM needed.

 

I went there to try to start it up before I pick up the car and I noticed that when I pulled out the oem ground strap, It doesn't seem bad at all and there was no corrosion. Anyway I replaced with one that I bought from amazon and still nothing happened. I literally thought that was it. once It didn't work out, I replaced it back to oem one but the amazon one looked like it's fried and it burned my finger when I touched it. I rescanned the code and there was another code popped up. A0B4 CAS: ENGINE START, STARTER OPERATION. Regarding the battery, He showed me the receipt of purchase from advanced auto parts about 2 weeks ago. I don't think it's AGM but it was brand new for sure. Is it because of the starter? Last time, that error code was not showed up.