At almost 180Kmi, the ADM has been screeching intermittently, and it stunk. It has apparently been trying to burn its protective fuse for a while, but not succeeding. I can't tell yet if it's strictly an internal failure, or if it was triggered by some external fault on the truck.
IF THE IMAGE IS TOO SMALL, click it.
UPDATE: after a little diagnosis & analysis of the overall situation, the owner decided NOT to attempt to repair this system now. The truck will run like a '93 F150 - no SRS.