Assuming my "back probe" connections were good, there was NO voltage at the terminal so next hop looks like that resistor dsexpress referred to. But it's getting dark, my light is friggin burned out (so I find now) and I can't see jack. Will pick up tomorrow. Getting this t/s tip from the hayn s manual chapter 3 (3-6). Will post results of that test. Getting closer to that heater control circuit WOLFIE. Does that circuit work with both the AC and heater controller ?