W124E320 guages quit wont restart
 

engine was running - guages quit - wont restart - buzzing noise somewhere

Hmm
 

I would guess from what you posted.

* The alternator failed = killed battery = shutdown engine.


.

Start circuit and some gauges (temp, oil, maybe one one other, can't remember for sure) share common circuit breaker. Think it's fuse number 5 or J... again can't remember for sure......

Just check the fuses carefully, I've been tricked more than once by one that looked good but wasn't!

Hope this helps.

J. M. van Swaay