Cummins isx not connecting to Scan tool

Hey all happy new years! Looking for an old iron expert here i dont got the cummins insite just the Snap on pro ultra crap tool it works on all our trucks for clearing codes and connecting to modules except this one and trying to figure out why and got no help, so here it goes firstly we were having a starting a problem with one of our t800 kenworth roll off truck its got a 2012 cummins isx basically it wasn't starting one morning and the rookie know it all mechanic hooked up a 24v forklift to the dam thing and let it charge for about a minute and started it no problem as he said and the driver took it, now the driver said the check engine light on about an hour after and got worried and now the problem begins, And so now when i hook up my scan tool i get no ecms detected and it also supposed to charge off the j1939 connection port and its not even doing that so i thought a fuse was blown so i checked the fuses underneath the floor panel d/s and there all dang good any other places to look for i really hope we wont have to take this to the dealer. Also the truck runs fine the no problems with anything else just cannot connect to the j1939 connection

 

Yes everything else is working the truck starts fine now as we replaced battery connections also installed them battery warmers and there looking good,, also if that fuse blew i wouldnt be able to start the truck if i recall blowing it one time. Will do first thing tomorrow appreciate the help guys will let you know whats going on i am 99.9% sure there is no power and ground as it should atleast charge my scan tool, i will check the readings and let you know what would be the next step if it doesnt have either .

 

Yes i checked them with a test light i