I have a 99 ls 400 I recently used the horn and when I did the horn started to sound when turning the wheel past a certain point both left and right. not sure how to fix......... any ideas as to why and how to fix?

 

Two possible causes that I can think of:

1: Faulty clock spring
2: Intermittent stuck contact

The issue occurred after horn operation, which leads me to suspect stuck contacts at the switch first. It is also easier to get to than the clock spring. However, I have never seen this, but I have seen many faulty clock springs.

Either way, I would check the horn switch contacts first and make sure it is in proper operating condition. This will require removing the driver air bag assembly from the steering wheel. If you are not comfortable doing this, I would defer to someone who is more experienced.

Hope this helps.

 

There is also a slight possibility that someone is pulling pranks on you.

 

It's a Lexus, it's being careful to warn others of your turn so as to have an accident. Of course I'm kidding. But it does sound as if there is an out of line contact point within the steering frame assembly located just below the horn contact.