I replace mine and it runs the best I remember to the front from the Thermostat and another one from the front AC to the Back AC. The Front AC is the control point. Look on page 21 of the manual. I just remove the lights near the thermostat and used a fishing pole (Elec). The front to the back was the hardest for my unit. You must pull the top covers on the AC and push a pull string down and then get on the inside and snag it and put to the light hole, then down to the Thermostat. Then again from the front and rear unit will a pull string hanging and tie the wire to each and pull up. Maybe Doug will see this later. He does it for a living and is more current than I. The telephone wire is just use to signal between the units, not power.
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