no reverse

Hi, I have an old EZGO. Forward works fine, but reverse does nothing. I've checked all the wires and connections, but can't find why it's not working. I bought a new forward and reverse switch, but I want to be sure my wiring is good. Can anyone tell me what is missing from my reverse connection?

2006 EZGO TXT PDS...all I did was pull out the 6-6v duracells and drop in new lithium ion batteries...straighten up the wiring...wrapped it up nice and neat ... fugured what the heck it’s wide open...well new batteries arrived and I dropped them in...hooked up the series for 3 and had my voltage...