update on initial issues.
the f/r relay control card was defective with rotted circuit paths on the pc board itself as well as corrosion on the relay connectors.cleaned connectors and did point to point wiring and it works well now.
seems some corrosive agent got on it and ate up the copper traces here and there.
the main controller card also had physical damage which required point to point wiring as well.

i'm still chasing gremlins at this point however.
truck work fine in both forward and reverse but if put in either reverse or forward without pressing the accelerator,nothing happens.
if i press the accelerator until i hear the micro switch and then put it in F or R it then works normally.adjusting the pedal so it keeps the micro switch just closed makes it work fine but drawback is that the drive system never shuts off until F/R lever is put in neutral.
tried known good main control board,voltage regulator and f/r card,accel unit with no success.
next step is to chase down bad connections and wiring i guess,or perhaps the R/C board!
truck has only 1100 hrs but seems to have had a hard life.