You also have to ask... how much is the Amtrak Chicago yards noted shoddy maintenance practices at play?I've heard before that the Chargers don't perform very well in cold weather. What exactly is wrong with them in cold weather? And whatever the problems are, could it be a design flaw or something?
Even the best equipment, treated poorly, will malfunction more often.
I’ll just note that while the SoCal, NorCal, and Washington Chargers have also had some teething issues... they’ve had nowhere as many issues as the Midwest locos.
So it’s the weather, or the yard, and my money is on the latter.