Electrical problems-
No trouble starting, or during continued operation.

However, when a user action causes an electrical load increases/change, (change lights/put on high beams) the power drops/resets, rebooting clock/radio (and feels like it tries to kill engine).

 

A dying battery can cause this. You state the engine cranks over normally, as in the typically high speed cranking? Not straining to turn the engine over?

Check the battery cables and connections for being loose, damaged, corrosion, etc.

Check negative battery cable connection to the chassis.

Check alternator wiring plus alternator ground path. This path is the alt being bolted to the engine.

There should be a jumper cable between the engine and chassis to serve as a ground path from engine to chassis. Check this.

Use a voltmeter to check battery voltage engine running (between the two battery terminals). Rev engine to 2000 rpm. Battery voltage should be somewhere between 13.5 and 15.1 volts. If not there is a problem with the alt.

If voltage OK, turn on those loads that would normally try to kill the engine and watch the voltage. It might change slightly but readjust. The alternator has a regulator that adjusts voltage to the load. If the voltage drops significantly the alt may not be putting out full current or a problem with regulator.

 

I Appreciate the well thought out help- thank you toyomoho.

It's (after ~3 trips- trying to get to the weekend, when I can deal with it) now not starting- no engine crank over at all. No door locks even. Seems weird to me that there wasn't a 'hard start' period, but meh. I'll be working on it tomorrow, and tell you guys how it goes.

 

If not cranking could be a dead battery, bad battery connections or cables, etc.

If all OK, check alt voltage output once running. Could be a bad alt.