Help, 4200XL Excavator Electronics?

[thebigo]

Question for those of you familiar with the RC4WD 4200XL Excavator. Gearbox on the left side track went out, so I Replaced both gearbox and motor. Put everything back together and fired it up, and now I only have reverse direction, no forward on both tracks? Pulled it back apart and found that i unintentionally stripped a black wire going to the motor, fixed that and I still only have reverse on both tracks. Wonder If it reset the ESC, when it grounded off the black wire? It's weird that both sides were affected?