x495 Electrical Issue

I went to start my x495 diesel this afternoon, and the glow plug and other pre-start lights looked fine, but it didn't turn over, at all. When I tried again, there were no lights, and it was dead.

I thought maybe I popped a fuse or the battery was dead. I pulled the battery, cleaned the connections, and this is what I don't understand: the pre-start lights came back, but they are dim, and of course, it doesn't turn over. Thanks in advance for any thoughts on this.

I have two other intermittent issues (2-3 times each year), that I don't think are related to the primary problem, above, but I thought I'd note them here, just in case.

1. Occassionally, after beginning mowing, the engine temp will quickly escalate into the red (within a few minutes). After shutting off the engine and restarting, the problem is gone.

2. Every once in while, and seemingly only on hot days, if I shut off the engine to take a break, it will not start again. During these instances, the engine turns over but won't start, and probably most importantly, I don't hear the distinctive "click" sound when I first turn the key. My guess is this loud click has something to do with fuel delivery. I'll pull the tractor into the garage or shade, and within two hours, it will start again.