Bought a ranger that didn't run. Trying to fix but when I engage the starter the ground wire gets hot and sparks. Suggestions?

 

Solenoid and or starter is shorted out ???

I would remove the starter and bench test it.
Also check to see if the positive side of the solenoid where the cable attaches isn't rubbing somewhere, same with the live bare cable that goes into the starter, check the insulation there.

 

all wires look good.

 

Starter is pulling too many AMPs

get volt meter and connect it to battery
A good battery will have 12.3 to 12.8volts

Crank starter
Starter will drop battery voltage down about 2.5volts, so no lower than 9.8volts, any more than that and starter or cables to starter are bad
"Cables to starter" includes BOTH ends of the cables, so Negative cable to engine needs to have a good clean bare metal connection to the engine

Cables can "look OK" but not BE OK.
They can corrode under the plastic insulation
Get some electrical tape and a razor knife
Disconnect cable at battery
Slice insulation back and remove it
Whitish powered residue is a failing cable
Should see clean metal under insulation
Tape it up if clean metal is seen
Replace if corrosion is seen