@grahamexp Weird, I removed the white and black wires from the plug on the bl touch end to check the crimps. Found no issue with the crimp. Then checked the plug on the duet end, again found no issue with the crimp. Put it all back together and switched on and now it works again. My testing the leads resistance didn't show any breaks or poor connections either. I am at a loss to explain this inconsistent behavior unless it is that internal pullup resistor.
