HELP! with Jeep starting issues

I own a Jeep Cherokee Classic that has 214,000 miles. It has been 100% reliable up until the last 7 months or so. My car is starting very sporadically. One day it wouldn’t start. I had someone jump me and it worked long enough to get me to the auto parts store where I tested my battery. It was dead. So, I replaced it with a BRAND NEW one made that month. Once the new battery was installed, my car still wouldn’t start. I tested the old battery I just took out from the cart it was on and it tested absolutely fine. I put the old battery back in and it ran fine for about 2-3 weeks. Then I had the same problem. I had it towed into my mechanic who said it was a starter problem. I replaced the starter. Since then, it has taken 2 cranks with the key to get the engine to turn over and has had the above mentioned problem multiple times since. It will start from a jump about a quarter of the time and seems to correlate with rocking the car backward and forward. (Desperate, you’ll try anything!) IF I can get it going from being jumped (and that’s a BIG IF!), it might be fine for several days to several weeks, and other times one I turn it off, it won’t start again for days no matter what I do. I replaced the alternator about 2 years ago. I hate to give up on it, but I’m running out of ideas and need a reliable car that doesn’t negatively interfere with my life. Any and all comments or suggestions would be welcomed!

Throughout all of that you never said what “won’t start” means. There are a lot of different things a car can be doing when it won’t start. So describe. You turn the key and …

Good point. Occasionally it might make a clicking noise, but that’s it. Most often absolutely nothing happens, no noise, nothing. No matter what it does, the lights in the interior of the car never stop working.

The clicking makes me thing that you might want to just check out your main battery cables - presumably through the battery & starter work the end terminals have been cleaned & attached tightly. But corrosion can hide under the insulation. You can cut some off to have a look, although at this age you might just replace them.

The complete deadness (other than the interior lights) makes me want to suggest that the next time it won’t start you put it in Neutral and then try it. This would suggest a bad neutral safety switch.

I wouldn’t be surprised if you had problems with both of these things and so are occasionally getting two different kinds of problems. These two things don’t really share anything - except age.

Thank you! Thank you! Thank you! Battery cables worked!