Yam G 19 jerky and want move

[ironhorsecowboy69]

I have a 2001 Yamaha 48 volt with a D&D motor, Alltrax controller. I have replaced pot at pedal with factory Yamaha piece, cables, solenoid,diode,resister, igniting switch ,checked brushes in motor, rang out all the wires . If I get a rolling start out of the garage cart take off and runs fine. When I go to back up you can hear the solenoid but get a red flashing light on controller .

[cgtech]

What is the sequence of the flashing light? It is trying to tell you something, and that something is listed in your Alltrax owners manual.

[ironhorsecowboy69]

The controller shows ready in reverse, then you apply some pressure to the pedal and it will go red. 5 red flashes means open field circuit, check field connections and motor's field resistance. .Now I'm wonder about the jerky and forward issues.

[ironhorsecowboy69]

I checked the motor from F1 to F@ an reads 1.2 ohms, i have continuity to A1to A2, A1 to body of housings no continuity, A1 to F1 have no continuity. brushes look new. Do you think the controller could be bad ?