I was changing out an old mercury switch dial thermometer for my AC to a chromotherm IV T8600D2028. I wired it as instructed with Y to Y, G to G, and R to Rc with a jumper to R. They also give a resistor to wire between Y and W. With this configuration the thermostat activates the AC but then goes blank. Any thoughts?

Remove the resistor

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Originally Posted by hixton

remove the the resistor

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Thanks for the reply but that didn't bring back the display. When I install without the resistor I can't get the display initially.