I recently installed a honeywell vision pro thermostat with the optional outside sensor. At first I used 2 extra conductors in my thermostat wire for the outside sensor but got some wacky reading. I ran a seperate shielded 2 conductor 18 ga cable just for the outside sensor. When I connected the sensor to the first thermostat everything was working great, when I connected the wire to the second stat I am reading 100+ degrees when it is 17 outside. Both were wired using the same 18/2 shielded cable?