I need some input on what might be wrong with my truck. So lately it wont start on its on unless it is jumped. Once it gets jumped it runs alright but whenever I turn the engine off and try to start it again it struggles to turn over and wont start unless jumped again. I checked the voltage of my two battery's and the one thats connected to my starter and grounded to the block read 14V. The other one which is just connected parallel to the first battery read 9V.
My only guess is that something might be wrong with my starter? And if thats the case would I have to buy a different starter other than a stock one for that truck, since the engine is a 427.
Any helpful feedback is appreciated