Well here is the information. I realized i had a second one and that one works with the same controllers... so they are not the problem. The current is likely VAC not VDC.... on the 2nd blanket, on preheat mode i get 115VAC running through.
When upplugged, the resistance of one loop is 0.68 K ohms ; and the other loop is 0.96 K ohms. Comparing with the blanket that does not heat, those readings are 23 M ohms.
Hence the real problem: the heating wires degrade with use ( and over time ? )... to the point of not heating at all.
Changing the heating wire is not something i am comfortable doing...