I have had a very similar gadget for a couple of years in my Vans.  The
biggest difference is it does not display vehicle voltage and it is only
run by one AA battery..

I'll be heading down to my local Radio Shack this afternoon to pick up a
couple...

I wonder how hard it would be to hook up to the Silver Socket
connector...?  Or would it make more sense to hardwire it to a switched
hot...

                JonR

          NH LiMBO area rep

             '87 Syncro GL
             '86 GL/Carat conversion w/sunroof