FYI, I recently dropped a new motor in my 2000 suburban. My check engine light was on so I took it to oreilly to get the codes read. Had a map sensor that was unplugged with was one of the codes. The other was a C0265 which was a somewhat nebulous code but pointed to issues with the ECBM or anti lock brake system. I also had issues with my headlights. The lights would not come on automatically along with some other strange behavior.
I read in a few places that there was a ground under the driver seat that attached to the frame and some people cleaned it up and it fixed their problem.
I pulled the ground and cleaned it real good and re-attached it. I also re-seated all the fuses.
The issue is fixed now and my lights are working properly.

Just thought I would put this out there for anyone experiencing a similar issue.

 

Thanks for the feedback. Might help others in the future which is what makes the forum work.