the instructions for installing a new curtis conntrol tell me to check the field resistance and assure that it is less then 2 ohms. My field resistance is 2.5 ohms. As I understand motors this has nothing to do with the brushes as the brushes are for the armature. is 2.5 ohms ok? how would this be changed short of rewinding the motor? possibly I didn't get a perfect connection on the probes??? but I scratched them around on the end of the studs.