This should help:
http://www.*******club.com/tech/12v.html
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If you are adding auxiliary lighting, a CB, or any other item requiring an ignition switched 12v source, there are several options available. One of the most commonly used is the SEO ACCY circuit, which according to the manual is "not used". This offers an easily accessible 12v ignition switched source. </div></BLOCKQUOTE>