I just replaced my throttle body unit on my 2009 clubman. With doing so the engine started right up then I noticed I was a quart low on oil I went to autozone bought oil put oil in then drove home. About a hour and a half later I went to leave for a friend's and now the engine won't turn over to start why would this be happening after replacing throttle body unit
They may not be related. How old is your battery. Have the battery tested, load toast not just checking the volts. It may be time for a new battery.
Were there any other lights on ? Did the starter solenoid try to engage ? And Welcome to Motoring Alliance !!