MTH 6 Pin Drawbar Question with long pin (Ground Wire) 3.0 PS-4 Southern 4-6-2

I need a MTH 6 Pin Drawbar replacement for a 3.0 Southern PS-4.  I noticed it did not have the long pin (ground wire) that runs the length of the drawbar. Trying to find out if the long pin should be with the drawbar or did this model not need a ground wire with the drawbar.  I have contacted MTH and my question is being researched.  Perhaps a member of the forum who has a 20-3464-1 Southern 3.0 PS-4 would be kind enough to help. Thanks!