I was flying a C414 and we experience a lost of an alternator took I to a different repair shop on the field they managed to put the new alternator on the airplane but they didnt know how to balance the load for the Alternators and they kept towing my airplane with the parking brake on. After that experience I took the airplane to Air Repair and they where able to balance the load from the alternators and the next time I had the issue with the vacuum pump they fix it without any issues.