Auxiliary belt snapped now won't start

[EJAP]

Citroen C5 Mk3 HY58DZT
Hello. Been a while since Ive been here but then my car has been behaving beautifully and is now approaching 150K. But. Today the auxiliary belt snapped and immediately the engine stalled. It will now turn but not start.
The AA man confirmed timing belt still ok and his diagnostics pointed to an open circuit to the crank sensor. This makes sense. However I assumed the belt, when it snapped, might have taken out the sensor wire but it all looks ok. Anyway I can test this with good old fashioned multimeter? Should I replace the sensor? Coincidence?
Help you lovely people... Thank you

[RichardW]

You probably can't check it with a meter, best to get it on a diag computer to find out if it can see the crank rotating, and if cam/crank are still in synch.

[GiveMeABreak]

I had my AUX belt come off due to a grease monkey levering the belt off previously whilst replacing the A/C compressor and using a screwdriver, which left a nick in the edge of the belt. I was on the way home, and noticed the power steering getting heavy, which was running purely off the battery all the way home. When I looked I could see the belt was completely off and mangled - but I managed to get it to my local who replaced it for me and no issues at all starting it.

So it may be coincidence, I can't say, but if he has pointed out the crank sensor, then that is the place to start and you'll probably need to get the battery charged up too, as the power steering will likely have depleted a fair charge from it.

[wheeler]

The belt may still be in tact but it may have jumped a few teeth, this will log cam and/or crank sensor faults. The sensor can be damaged when the aux belt breaks but you can normally see physical damage on it same with the magnetic pickup. First thing I would be doing is get the bottom pulley off & check for belt debris in there. Rotate the engine by hand & inspect all the belt & teeth. Personally if it was me id remove the timing covers to check for any hiding bits of debris that may dislodge later unless i had the broken belt & there were no bits missing from it.