36V TXT will start to move then stop

[Brap20]

Sorry if this had already been covered but I couldn’t find my exact situation. Little background, 2003 36v series txt. New lithium batteries, new HD F/R switch, new high amp 36v solenoid, all new 4ga wiring, and new GE 700 amp controller with ITS controller. It was on jack stands when I installed all the new parts. Got it together, tuned it on and everything seemed fine. I gave it a little gas to make sure it moves and modulates the throttle but didn’t get close to wide open on the stands. I get it off the stand and start to go and it starts to move for a split second and then there’s no power. Solenoid is still clicking with movement of the pedal. Now I’m lost. The only thing that was questionable was the wiring to the ITS controller. There’s no simple plug in for the controller like all the diagrams show. Mine has a square 4 pin connector. So I tried my best at wiring directly to the controller. Thanks