Cold weather problem: Car cranks, but doesn't start (up to 15 minutes).
All accessories don't function - low/no voltage on gage.

As you play with the accessory switches (roll down windows), voltage increases. About 1-2 volts until normal voltage. Relays gradually click. Window motor gradually hums.

Roll down windows (takes a minute or so) - car will then always start.

I'm thinking bad ground. Thoughts?

That or a broken plate in the battery grounding out?