Q: Gauges go the left, randomly dies, and sometimes won't start.

Hello. From what you describe, it would appear to me that your vehicle may be experiencing some sort of electrical or wiring issue. It may be possible that once the temperature reaches a certain point either a component or wire is overheating and causing an issue. The electrical resistance of wires and components goes up as the temperature rises. If the temperature rises too high, or the components are old or worn, the increased resistance may block the flow of electricity, causing all sorts of issues. I would carefully examine the engine bay for any signs of worn, frayed, damaged wiring, starting with the battery cables. If everything looks okay then there is likely an electrical component that may be failing and causing the issue, in which case I would recommend a professional diagnosis to pinpoint the cause of the stalling issue.