So I just finished an engine swap in my 04 2.4L TJ. Tried to start it and just got a loud cranking noise. So I tried one more time, but just more cranking. It sounded like the starter wasn't working properly, so I took it to the local auto parts store to get it tested. It passed all the tests and they said it was working just fine.
I put the starter back on and wired it up. I took the bottom plate of my transmission off and got under it. My roommate tried starting it, more noise but it looked fine. The teeth came out and turned the flywheel a bit. he tried again while I watched the drive belts. The belts moved a bit but no start.
We thought, "maybe the battery just doesn't have enough power to spin the flywheel." So we got the jumper cables and hooked his battery to mine. Tried starting it again, but all we got was just more noise.
I'm not sure what to do now... here's a video of what it sounds like.
Any help is greatly appreciated!