Hi all. First post here. I've had great experiences on forums in the past and understand the basics, so will try to give whatever info I can. I'll supply whatever else is necessary.

36v 18 cell battery is freshly charged and showing 37.5v. 2v on each cell. Recently equalized on charger. Battery looks good, all cells showing 2v. E50XL is from 1990. It has dual SCR controllers.

With key on, pull back on hoist handle (or any one of the three) and an error code flashes "- 142" then quickly flickers and disappears.

1. Truck won't move forward or reverse. It did move it two days ago prior to cleaning it with degreaser and a hose, so it was driving recently. I covered the motors best I could when I washed them, but I'm sure some slop got past. The truck was caked in a 1/8 of thick black filth and battery acid overspill.

-When put in drive or reverse, I can hear the forward and reverse contractors slapping around when I hit the pedal, but no movement. I've tried from the ground with the seat tilted up, and from sitting, but no luck. Battery is out of truck on side.

-Checked the four fuses in the rear, all are good. Pulled and verified them with a multimeter.
-Zero movement of electric drive motor. Battery has been removed and is sitting next to truck, and is connected.

What can I check electrically to help isolate the issue? I have not put it in forward, pressed the accelerator and checked the main drive motor for voltage. Lots of connections and not sure which to check.