Can not locate the crank sensor

I took this car in p/x from a friend who was desperate for a working car,
Basically he changed the wheel bearings and after he finished went to start the car to take it and test drive it but it wouldn't start!
He tried to locate the crank sensor after being told this is likely to be the problem, I spoke to a few mechanics and they all say the same!!!!,

However I jacked it up onto axle stands and spent 2 hours underneath trying to find the sensor to no avail !!!

Anybody worked on these and know where it's located it's driving me insane as it could be a simple fix but can not find the bloody thing!!!!

Any help much appreciated,

If you have any pics even better!

Thanks guys