Quote Originally Posted by 36 sedan View Post
Ken, certainly no disrespect intended, but I believe we have derailed. The intent of my drawing was not to make a universal alarm system, and of course a separate ground wire would be needed for plastic. Rather, my drawing(s) represent a simple solution to the OP’s question for a latching relay set up that would control a 12 volt horn mounted under his seat that would activate when the doors are opened without being overly complicated. I believe I accomplished that.
I’m sorry for any miss givens, miss understanding, or confusion, anyone is welcome to use or lose the design at their choice. I bid a fair goodbye......

No disrespect intended or implied. I freehand most of my diagrams, not that computer savvy, and usually end up constructing them on a breadboard to iron out my mistakes.
I checked out delay units on EBay and found this dandy little item https://www.ebay.com/itm/12V-DC-Mult...sAAOSwNYZerVWg