Had a call that a w/m was not filling ..I fitted new brushes to this a while back … Now i checked everything out and found that the heater was down to earth it was 0.06 meg ohms ..so i disconnected heater and tried m/c and it filled right away no problems..
Now if i had not had a meggar then i would not have discovered this problem because heater tested fine with multimeter but failed on low insulation.
Funny thing is that i tested the heater a while back after i fitted new brushes and all was fine …This was an old w/m so would not have found any error codes to help me out.
What could have made it go down ,could it be that it is an old m/c with original heater as everything else checks out fine .