You need a voltmeter. If you’ve been repeatedly trying to start it without success you may have run the battery down as well given your high temps.
I know, you didn’t need to hear that.
:>(
Brand new battery. Not even two weeks out of the shop (for what that means) and it’s not lagging when I start it. It starts just fine the first time, but I try to start it when I have been in a store for 10-30 minutes, and it grinds. I’ve taken to backing into my spot so I can clutch start it if I need to.
The starter (rebuilt) is less than two years old, and I don’t drive the truck in the warmer part of the day because it has no A/C, and I’m a ol’ lady. A/C was never installed, as the truck was destined for Puget Sound, WA.