Need help, no crank no start

Hi - Dave here, contributing to RepairPal and providing expert advice since 2010. I appreciate your problem, I have to say that I would not recommend replacing anything until you can determine where the problem is coming from. $300 is definitely something you'd prefer to keep instead of investing in a cable you do not need. When I think of things preventing the starter motor from engaging, first, I ask if you have normal lights and power inside the car. If you do, then I think about what may be preventing the load of the starter from engaging. The transmission lever position switch (sometimes called the "neutral safety switch") may not be showing the vehicle in "park" or "neutral" gear. This is one possible cause of your starter motor not engaging. A diagnostic tester should be utilized to monitor shift lever position actively. If you are certain the "new" starter motor is good (and they definitely aren't always!), then sure - you may have a voltage drop due to cable issues. But I would want to measure this with test equipment or a voltmeter. The ignition switch could be a concern, and anti-theft systems should be considered, such as with the key and it's need to be programmed properly to be used. As you can see, there are multiple possible causes and angles to attack this from. Without having the car in front of me, I can't really give you more guidance. However, you could reach out to a shop near you: https://repairpal.com/auto-repair-near-me Click the link to find some shops near you who can help out! Or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.