[Help] Tractor No Longer Cranking

Hi, I’m in the process of preparing my dads old tractor. I had it running, but the glow plugs wouldn’t work, so I’ve been in the process of fixing that. Changed the relay and it was cranking fine (didn’t fix it in case you were wondering) and went to start it for my weekly start (isn’t able to move right now so I’m just starting it weekly to make sure it keeps up), so I shot some ether in, went to crank, and all I got was a clunk and the entire tractor lost power. If it sits for a couple minutes it gets some power back but just repeats the same thing. Since it still gets power after sitting, and I also checked some places where 12v is, I don’t think it would be any of the fuses. And since it loses power I’m not suspecting the starter. I checked the battery and it still measures 12.56v. I’m kind of out of ideas. Spun the fan at least half a rotation so it’s not locked up. Any help would be great!

It’s a 2006ish TYM T233HST if that could help anyone aid me in diagnosing