Any body care to speculate on why my AC will work only if my EHA is disconnected. I show no voltage to the EHA, no continuity in the wiring through the plug, yet when I plug it in , the AC compressor clutch won't engage. I have looked at the schematic for the compressor and see no connection. Also if I remove relay"D' from the rely box, the compressor will not work. This relay engages when the EHA is plugged in. According to the Service CD, relay "D" is for the headlight washer.