THE MAGIC PIXIES ARE ACTING UP AGAIN (engine stalls under electrical load)

HOW IT ALL STARTED...
I was driving down the street after an idle time of 6 min and a driving time of 4...
The service 4wd light came on the check engine light was already illuminated...
I slowed down for the car directly ahead of me and the engine quit...
Initially, I would only get a solid crank and no start but I was able to get it running...
SYMPTOMS
The engine would stall out whenever...
Switching gears,
applying brakes,
actuating windows
electrical process BESIDES RADIO and steering adjustment
WHAT I HAVE NOTICED/TESTED
The ignition chime sounds like it is browning out until the fuel pump stops,
the voltages read fine off the battery running and not running
The battery has been load tested (good).
All fuses have been checked.
While not running the acc. Battery cable was checked for continuity(good),
turning on the hazards or the rear window causes the trunk glass release to actuate for each pulse
ac compressor will randomly cycle while turned off
SMOKING GUN?
The headlights glow dimly when the ignition is turned on and the lights are off. Attempting to turn on the lights results in a stall
MY IDEA
bad ground or bad acc supply line
SPEC'S OF TRUCK
1999 GMC Yukon 220000 miles
5.7 Vortec W/EFI
4l60e
Bad valve seat on cylinder #8 cause for CEL
tons of coolant leaks but if it's only filled with water who cares (I know it will cause internal rusting and freezing in winter (it is winter))
exhaust leak from broken first exhaust hanger (post first o2 sensor pre-cat and secondary o-2 sensor)
I was driving down the street after an idle time of 6 min and a driving time of 4...
The service 4wd light came on the check engine light was already illuminated...
I slowed down for the car directly ahead of me and the engine quit...
Initially, I would only get a solid crank and no start but I was able to get it running...
SYMPTOMS
The engine would stall out whenever...
Switching gears,
applying brakes,
actuating windows
electrical process BESIDES RADIO and steering adjustment
WHAT I HAVE NOTICED/TESTED
The ignition chime sounds like it is browning out until the fuel pump stops,
the voltages read fine off the battery running and not running
The battery has been load tested (good).
All fuses have been checked.
While not running the acc. Battery cable was checked for continuity(good),
turning on the hazards or the rear window causes the trunk glass release to actuate for each pulse
ac compressor will randomly cycle while turned off
SMOKING GUN?
The headlights glow dimly when the ignition is turned on and the lights are off. Attempting to turn on the lights results in a stall
MY IDEA
bad ground or bad acc supply line
SPEC'S OF TRUCK
1999 GMC Yukon 220000 miles
5.7 Vortec W/EFI
4l60e
Bad valve seat on cylinder #8 cause for CEL
tons of coolant leaks but if it's only filled with water who cares (I know it will cause internal rusting and freezing in winter (it is winter))
exhaust leak from broken first exhaust hanger (post first o2 sensor pre-cat and secondary o-2 sensor)
0