Hi Liam

Try your miltimeter on A/C, you will not be able to see if the signal is corrupt but I would have thought you will get a reading of the average.

I don't normally use this method but I have just tried it on a fiat stilo for you that has got crank sensor issues when hot, but is starting at the minute.

I got a reading of 3.34 cranking with the sensor disconnected.

Try it with the sensor unplugged and go across the terminals, then at the ECU.

Try it on a car with no issues.

This really is a job for a scope.

Have you managed to confirm the tests from my other post?

hth
James