ST-i Autoguider With Old Astro_Physics 800 Mount

Has anyone had any success getting a ST-I to work as an autoguider through one of the older mounts (e.g. Astro-Physics 800) ? I have a Relay Adapter Box that I use with a ST2000 camera, but the ST-i will not work when I connect it to the Relay Adapter Box. I did some research on this and the ST-i does not have a 12V DC output like the ST2000 does. I tried rigging up an adapter to combine the 12V DC and ground pins from the ST2000 with the four relay out pins from the ST-I. I plugged this into the Relay Adapter Box, but this did not work either.

Any ideas or suggestions would be appreciated.