Zanussi ZWG 7160 P Fault

I have a Zanussi ZWG 7160 P not finishing any cycle and won’t release the door catch.
Error code E52 (Tacho coil) is showing, have measured resistance and it’s at 174 Ohms when still and rises when I spin the drum by hand. This seems about right (the only info I found said it should be at 184 ohms but the fact it changes seems to mean it’s working)
The machine will rinse and drain but won’t spin on any cycle.
Tried measuring voltage when it’s set to spin, but I’m not sure if it’s actually trying or not. Either way, only have 56 volts between either brush and earth and nothing on any other cable on the motor connection plug.
Brushes are fairly worn but not completely gone, I guess I’ll change them first but any other advice greatly appreciated.