My battery went dead in my 2004 rx330. We tried jumping it but the horn continually went off and the ignition wouldn't acknowledge the key. We have replaced it and only the dash lights up, and locks work, but wont start...anyone have any suggestions

 

Here is a post with some insight into the immobilizer, does your starter engage? Maybe a fuse blew when jumping the dead battery.

https://www.clublexus.com/forums/rx-...er-system.html