hi

ed starter motor sounds like it wants to turn but it wont.

been told it is not getting enough power,, would it be worth putting the thin starter cable directly on the battery as well as the thick one to see if the cars wiring harness has the problem.

whats the chance of the cars wiring harness being the problem.

whats the chance of the solinoid being the problem.

would a old starter relay cause this problem

have a ba starter motor and that does the same as above too

look somewhere else, battery, earth strap, etc.

Theres no way a thin wire will help the huge +ve cable you have going there already.

Get a BF starter and be done with it.