Thank you Stuart.    Your comments are very helpful.  Just finding the Vanagon wiring diagram pertaining to the power locks was tricky.  
I eventually found it on 97.163-164.      I think that wires going to the Valet unit that are spliced into van ignition switch wires are the ones that are the most important (yellow and Red).    I have not seen or heard a siren yet so it may already be detached. 
I will attempt to map the colors as you have suggested tomorrow.     Gee this thing is a pain but I can understand that it needs to be tricky to defeat  for it to be worthwhile.      Thanks again   Steve

On Dec 5, 2013, at 10:10 PM, Stuart MacMillan wrote:

> This is a feature of an alarm system. You can't defeat it unless you remove
> it.  The manual seems pretty complete to me, just like the one that came
> with the Avital unit I installed last year.  Just map the colors on page
> five with the Vanagon wiring diagram.
> http://www.directed.com/guides/manuals/ig/valet/N711T.pdf   You won't use
> all the wires provided in a Vanagon installation, and this sounds like a
> professional installation.  PO probably paid $500 to $700 to have it
> installed.
> 
> If you don't need the alarm just clip the wire to the siren and use it as a
> door lock controller and ignition cut out just in case.
> 
> Stuart
> '85 Westy
> 
> -----Original Message-----
> Snip:
> . . . . .the only thing that bothers me is that the door locks operate
> about 3 seconds after ignition key operation  and I have not found a way to
> defeat that yet . . .
>