Hi everybody, first post here, looking for help.
Any insight is always appreciated.

So I got this beauty used, and I've fixed up a bunch of bits.
Now I have an intense problem that I can't logify.

The key won't turn in the ignition.
Must be the wheel. Nope, wheels may be locked, but moving it around doesn't make a difference.

Earlier today when I encountered the issue, I initially considered the battery despite the clusters all reading properly. The LED screen displayed, radio worked, everything was golden. But the key wouldn't turn.

We jumped it off a hefty truck.
The key turned, the car started, the onboard cluster died. No LED screen, no gauges. Signals didn't work, etc.

The truck had left when I turned the car off.
The clusters worked again. LED screen was back, hazards work, radio plays, etc.
Key doesn't turn.

I hooked up another jump from a four cylinder with a much smaller battery and the key wouldn't turn.

So I assumed it must be the key fob.
A weak fob battery. So I replaced it.
No response.
Then I tried larger batteries in the fob (cr2032 instead of cr2025).
Still nothing.

I've just now tried another jump off an SUV, with an equally cheap and smallish battery to no effect.
It was left hooked up for over ten minutes with intermittent attempts to no result.

The clusters and electrical still seem to work fine. The lights all function, on and off without issue.
Radio, hazards, etc are all functioning.

Key won't turn.
Car won't respond to key at all.

Heeeelllpp!!!

 

Read my post at 02 C240 Won't Start. It might give you some clue.

 

Turns out the fob was broken and had some water damage.
The rep who helped me at the dealership took a moment to remove the circuit board inside the key, and out popped a piece that had broken off.
We fixed it with a piece of scotch tape, slotted the chip, put the batteries back in (a cr2025 and a cr2032) and shabang!

Car works normally again.