Jeep Grand Cherokees battery draw

Looking for some tips to finding a intermittent draw on an '00 Jeep Grand Cherokees 4.7.
Daughter says she's seen the headlights flash on at night. What could trigger that? I've also read lower than battery voltage in the BCM. Does the BCM control the automatic headlights?
Another weird thing, which may be related, I've noticed is the service millage reminder will jump around. I have about 3500 left to go on a 5000 miles service. It's jumped to less than 2000. If I pay attention, it'll jump back to being correct. Where to start? I only have the "Red Brick". Thanks for your feedback!

First thing to check is battery ground to chassis and engine to chassis ground also the battery positive and negative connections. if nothing obvious check alternator connections.

Thanks Andy
If I drive it regularly, the charging system can keep up with the draw. I'll do a voltage drop test on the battery connections.
So, what are your thoughts about the headlights randomly coming on with checking the battery cables?

 

 

Thanks Chad! I'll check the wiring diagrams out!

Headlights randomly coming on would make me suspect a sunlight sensor starting to go bad. Otherwise a faulty ground could be the other possible cause. If you have a scanner that can read live data in graphing view look at the sunlight sensor/ambient light sensor data pids. See if they go squirrelly when headlights go squirrelly. If they don't then move on to checking relay and wiring.

Thanks, I'll look into that.

The low beam relay is drawn differently than the other relays. This may be a solid state relay. They're easy to distinguish by looking at the bottom of the relay. If it looks glossy and doesn't look like it could be taken apart like a regular relay, then it's likely solid state.
I bring this up because I've seen many GMs using similar relays with that exact same symptom.
Headlights come on with the car parked, intermittent battery drain. 

Noah

Thank you for posting this information! Definitely something to look into!
Edit.

Another member left wiring diagrams and on those it shoes both relays as mechanical. I wonder which one is correct?
See the attachment. 

Thanks guys!

 

The solid state looking relay is for vehicles with DRL. The regular relay is for those with conventional headlights.

Thanks for the reply!