Speed sensor testing?

I've had an intermittent speedo which has now died. Worked abit by wiggling the cable but now nothing. checked the rotor which was ok and did the sensor test but I used pins along the wires in instead of the manual test. On the pink wire I got 4.6v and on Orange and green 11v. When the wheel is spun I expected the pink voltage to go up. But in just getting the 4.6 with no movement. Is there another test before thinking this sensor is dead?
Cheers for any help.
Also its a k3 model.

just another question. if i got a k5 sensor and put the 4 pulse magnet rotor for my K3 in would it read correctly? im guessing the magnet is the only different part or is the sensor itself different?