Yes
The alternator may not be charging. There may be a bad connection from the battery positive or negative to the vehicle circuits. The headlights large current draw is causing the voltage to drop below what the computer needs to operate properly
no a egr valve would not make a dead battery. a bad alternator or maybe a bad connection post to battery would make it die ,
Any wire or other metal object which touches the positive (+) connection of the battery AND the negative (-) battery connection OR the metal bodywork will spark
There are several things that can make your headlights not work. First the might have blown a fuse, or maybe the bulbs burned out, or the battery might have died.
You will need to first disconnect the electrical connection behind the headlights. You can then detach the cover and dry out the headlight. Make sure the source is not a cracked lens.
There's one screw on the outside and the rest you get from under the hood. On the drivers side taking out the battery will make getting to the bolts easier. You will have to unplug the electrical connection too.
bad connection, less current to computer? mis information almost as if a bulb in a bad light switch works when it wants to
Sounds like the battery went dead or you have loose/dirty battery connections.
I might start by checking the ground wire of the taillight assembly. Make sure there isn't any rust that is preventing a good electrical connection to the chassis ground.
It could be a bad battery battery does not have enough power in it to make starter to work.
if it slips, then it does not charge the battery, and you might not make it home if you are driving home at night with the headlights on.
Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alternator belt. If the battery and alt test ok than check the connections to the alternator and battery.