I've attached the layout of a system to detect car windows that are not closed as the driver opens his /her door.
I would like to put in an audio alert as well but can't get a buzzer to work on it,where & how should i connect a buzzer in this circuit ?
Thanks

 

Read the tos first.

If this is just educational we can help but if u plan to use it in a car, we cannot help u. Sorry. Rules of AAC prohibits automobile modification

 

The owners of All About Circuits has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

This thread is against the AAC forum rules, Chapter 6, as seen here:

6. Restricted topics. The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

• Any kind of over-unity devices and systems
• Automotive modifications
• Devices designed to electrocute or shock another person
• LEDs to mains
• Phone jammers
• Rail guns and high-energy projectile devices
• Transformer-less power supplies

This can be found in our Terms of Service (ToS)

Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

Please try to understand the reasons behind this action, and feel free to browse and use the forums.

You might find answers to your questions in one of these forums:

http://forum.allaboutcircuits.com/showthread.php?t=54400

Another good forum that shares many of the same membership is http://www.electro-tech-online.com/ . Good luck.