Vintage RC - Tamiya Desert Gator Off Road Vehicle & EXPEC TTU-03 Remove Control

Selling for my Father In Law.  I do not know much about it.  It powers on and wheels turn but I cant get it to drive right.  The wheels and acceleration do not respond as I would expect them to.  Could be something I am doing wrong or could be a big issue, no clue.  Selling AS IS.