to get Ed's quote for a warrantied repair;
Rebuild or replace all the directional contactor tips, and also the "d" [as in dual motor contactor, most likely mounted in the middle between the 2 sets of directional contact assemblies] and confirm or replace all the drive motor brushes.
my W.A.G. as to what is happening;
either;
one of the "at rest" positions the contacts or not making good contact (this would be far more likely if the problem was related to one direction [forward or reverse] or the brushes are just barely "worn out" and the greater current at bypass (1A) is enough to complete a circuit through the drive motor.