No crank no start

I have a 1999 F2 50 ford been
converted to CNG starter went out on
it I put a new starter in it so annoying
on the firewall a new battery and it
cranked couple times I got it started
and drove to the store I had to bridge
this Illinois to start it and got it home
and now it’s a no crank no start I’ve
traced wires I’ve done everything I
could possibly think of to do it
replaced all the fuses in the vehicle
Have charged batteries and put
brand new batteries in there and still
no crank no charge no start what
seems to be the problem