Ive been working on multiple types of powerd Jack's and fork trucks for a while now and have never been so stumped on something... I have 2 wp3000's that act like they have ecr loss... they barely move and it's small sporadic jerks at best... my 5v system is fine. I've tried a new ecr. I've replaced access 3. I've tried another motor. I've tried a new pot. Tried an all new handle with all new parts. I cannot see anything in the wire harness to suggest and used a meter to verify... if anyone can help it would be very much appreciated... if it helps they both worked just fine. One sat quite a while inused and the other one the operator said he hit a bump and it just started acting up. I work on a fleet of over 100 and never been so puzzled... thank you