E34 didn't start.

Full tank of Shell 89, not sure when battery was last replaced. 22 degrees F outside. Last driven four hours ago.

When key is twisted, has a grinding sound.

All accessories work and lights are bright. Unlock/Lock works fine.

Hooked up jumper cables to running Pontiac. Positive on the good first, then positive on mine. Negative to good then, then negative ground on my strut tower bolts. No effect.

What's wrong? February has not been kind to the E34.