Can someone help? I need to drive my dart tomorrow

If its been a problem and getting progressively worse then its the ampmeter causing a load,ever increasing until you get to where you are now. Yes, it is an instrument to warn you of a charging problem.
For example if you used car for jump starting another vehicle or have a habit of running battery down or run a bigass amp to power a set of subs in the trunk, the weak link will rear its ugly head in short order.

All this hogwash about diagnosing faults has merit,but if car is dead due to the wire in the photo, you need to patch it so you can find your trouble.
Checking voltage before and after its running and with all the accessories off and on will indicate the condition of your battery and charging system.

Amp meters have been gone from dashboards for over 30 years for good reason....
Over-analysing the situation isnt getting it fixed.
Unlike todays electrical systems with hundreds perhaps thousands of feet of wire connecting 20 or so computer modules. Computer bus circuits with rendundant wiring, thats where its at...resistance is futile,failure is eminent.