Richard,
I mentioned it in the first response – at the left side of the trunk over the left rear tire housing arch – you will have to remove the Trim panel between the spare and the metal brace, and reach up behind forward a bit behind the brace and you will find it (use a flash light first to find it)/ You will find the 3-socket test pigtail and the yellow ABS Main Relay there as well. The ABS main relay could be the problem if it has failed, as there will be no power to the ABS system. Richard, do you have an electrical schematic for your ABS, and do you have some knowledge of how to use a Volt-ohmeter?