- what vehicle (base or support) Here is a link for the complete IAC rebuild guide that is if your IAC is of the type shown in that guide, <a href="http://www.cadillacforums.com/forums...step-step.html">http://www.cadillacforums.com/forums...step-step.html</a> There is a guy who shows an IAC rebuild for a different IAC which may be applicable if the above is not applicable to your case.