this thing has amind of it's own
 

My wifes 2000 Tahoe the keyless entry remote stopped working for like a week. we put a new battery in there and it still did not work, then out of the blue it decides it wants to work. it's ok that it works but why would it not work for a week then start working again, other than having a mind of it's own.

Possibly a short. Start checking the wiring. The only way for it to be off than to come back on randomly.