voyger trans ground strap where is it and more

Hello got a van that been sitting for a year trans problem,orginal owner was told needed a trannie, 150 k miles on unit never serviced, 3.3 engine. ok I put a battery in it and started right up took it out shifted 1/2 then slipped into a netural , then I slowed down and was locked in sec. ok have reverse,fluid dirty but it goes,been reading some of the stories about what to do,one was ground cable should be replaced ,where is it? can I make one to the trannie and the body? Im going to change the fluid filter, if this dosent work what should I do?sensor ect. than :smile: :smile: k you frank.

I had to replace the ground strap on my 99 3.8 L the other day.
The ground strap I replaced was on top on the passanger side of the engine, above the serpentine belt area.