About 1,200 miles into my trip to Wisconsin and back when the yellow ABS indicator lamp comes on. It's only a yellow warning, so I finish my trip, then go to the ACA tech library for help. There it is..the Meritor Wabco ABS manual. I found the switch needed to do the blink code diagnostics in the bottom right corner of the firewall, clearly labeled, by the passenger's right foot. The diagnostic sent me to the Driver's front wheel, where I found a broken wire. Repaired the wire and used the same switch to clear the fault code and the light went out as soon as I drove the required 4 MPH.
Many thanks to those who have put the time and effort into that tech library.