bobcat 84-03 error code

I recently bought a newer used sg-30 stump grinder then had to get and install the $400 14 pin harness and black box for my s300 bobcat to run it. So I have never previously used any electric attachments with this unit. The grinder kicks on and spins fine, but will only move right and down. When I try and move it left or up it kicks off with the 84-03 error code saying "ACD ouput "E" signal wire #5200 voltage not present when voltage expected." When we unplug the harness from the grinder the code remains, but when we unhook the harness from the bobcat it clears itself and hydraulics work again. So we are thinking it must be the bobcat side with a faulty wire? We also checked the grinder harness with a test probe by applying power at the solenoid and checking at the plug and they all worked fine. We did notice the bobcat side plug has only one constant hot which is letter K, but the grinder only uses letters b,c,d,e, and f. But we have no schematic to go from. A schematic or some direction would be greatly appreciated..