Ignition on permanently

[Jim Perriam]

changed Battery and alternator,  now ignition on permanently.  

[Mr Vlad]

Hi Jim. Welcome to the best Lexus forum there is. Unfortunately you've posted in the wrong section. Your car is a gen 2 IS. This section is gen 3.

Who changed the Battery and alternator? I suspect a wire has been misplaced or not connected. 

Hopefully a forum moderator will move this thread to gen 2.

You'll get more replies.

[steve2006]

Hello Jim and welcome to the LOC.

I’ve moved your post to the correct model forum, hopefully you will get more responses here.

A few more details would help us help you as Vlad mentions.

Hopefully not a reverse Battery polarity incident!
Common problem is the main fuse blowing, rated 150A located in the engine bay fuse box.

Unfortunately not a push in and out but hardwired, they are bigger than a standard fuse with a clear plastic window so easy to see if the link is broken but not easy to replace.

Looks similar to picture below.

[Herbie]

I would hazard a guess at a blown or faulty rectifier. The light is permanently on because it's now getting a backfeed from somewhere, which is something the rectifier should prevent.