1989 Mj fuel pump issue. Low voltage/ bad ground

[betterthanbroken]

I've seen many posts about fuel delivery issues. I have an 89 Mj that has many PO mods and fixes so it is hard to diagnose things.

Current issue: was wheeling last weekend and hit hard over a jersey barrier, truck went dead, crank but no start and no fuel pressure. Many curse words later, chasing connections etc, this is what I have.

10.56v in at ceramic restrictor. Fuel pump (out of tank) will crank at 10.5 but only if hard grounded with jumper I fixed to battery.

Question. Does this pump only operate if grounded to the tank?? Stock wiring will not work. I have redone ground at rear taillight.

Thoughts?