Hello. Checking to see if anyone has also experienced this. With engine running, attempt to turn headlights on and engine dies, as if it were a kill switch, and will not start. Some research suggested to remove park lamp fuse. It worked, but now no running lights except headlights. Brakes and hazards do work, but my concern is with tail/marker/license plate and front ambers. Can this be as easy as a bad ground or am I looking at a full ECM replacement again? Thanks , DRG

Check the interior ground in the driver side kick panel. Then the ECM and PCM grounds are on the passenger side battery.

It is likely to be a poor connection in either the grounding circuit or the supply circuit.  In either situation, a poor connection can become worse when another electric load is turned on (the headlights in your case).  Definitely check out all ground connections to body, frame, and engine as well as battery cables  - both positive and negative.

 

- John 

If you grab the FSM from the download section it will list the ground locations. Also don't over board with grinding paint off everything. A rusty surface can be worse than a painted surface.