make sure the diode is not shorted with your multi meter (you will have to remove 1 Leg of the diode from the coil to test this). also make sure you have the wires on the coil and diode the right way around.
the red and orange wire should be at the end of the diode with the line and the blue and red wire should be at the end without the line.

make sure the fuse that you install is a 250ma SLOW BLOW fuse.

if the above is all fine then check if transistor (mosfet) Q50 on the cpu / driver board is shorted.

(the schematic I have is not very clear so i hope I have all of the above right)