maybe someone can help been working on a 7bpue 15 orderpicker. Complain was orderpicker won't lift code 26 on the board l checked lift pot checked OK as far as voltage but l ordered new lift pot from Toyota and installed in handle after l calibrated and everything was OK. then two weeks later same call no lift same code checked pot all voltages OK. l than ordered carriage manager card from factory installed and truck calibrated pot again. One month later same call. I than installed filter on battery and new static strap. same problem. what am l missing any help would be appreciated.