Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.
This might be what you're looking for. Appendix H has wiring diagrams and starts on page 2677. The main diagrams themselves though are at the end, it looks like they start at 2975
https://www.hmmwvinscale.com/HMMWV%20TM%20%20-24%20Vol%202.pdf