I fixed (with the kind help of the gentlemen here) an issue with directional contactors not engaging, and got this truck working as expected.

Wiring diagram here: imgur.com/a/9ReVA (Copy and paste into browser address bar since I can't post a full URL link here)

However, after about 10 minutes of working it, I'm getting smoke from the large resistor that I'm presuming controls speed of the traction motor (?) and probably need to replace it. How can I determine the values I need for this resistor, as I'm fairly certain I can replace it with more standard modern resistors.

Also, should the hydraulic pump be working all the time? When I first got this, it seemed like it only came on as I used a control, then shut off a few seconds after demand. Not sure what the correct behaviour for this might be. From the diagram, it seems like it should be on 100% and perhaps the earlier behaviour was just a power issue.