Anti theft?

With the light on I would start with the security system wiring. These are the diagrams for the SKREEM module and the cluster inputs. The grounds for the door latches all meet under the dash. If you don't see a door ajar warning that is likely OK. Next I would run all the fuses, there is a good chance that if mice got under the TIPM and chewed they knocked out a fuse or two. because there are short jumpers under it as well as main wires. So go to the fuse boxes and test with the key off then key on. See if there is a problem. https://www.2carpros.com/articles/how-to-check-a-car-fuse
As for a wiring diagram, the best solution there is to get a short term subscription to either Alldata DIY or Mitchells DIY service. You get them for a single vehicle and get the same access we use. Then you can go in, find the diagrams and then print them to pdf files for later use. (you could even go through and print out entire sections) The advantage to that is you can blow them up much larger without all the distortion.