Hello Roibeard, I have re-tested the flywheel diodes & have discovered a problem. 1 diode has a value of 1.119m ohms in one direction, switch the leads around & I get open circuit. I tested the other diode, I have a value of 97.3 K ohms in direction and 79.6 K ohms in the other. The book I have says test in 1k ohms range. The diode should test approximately 3k ohms in 1 direction & no continuity in the other direction.