Help With 2nd AC

[jsk]

I, with some help, installed a 2nd ducted AC in front bedroom. The AC, therm., and flush mount are all Coleman. Unit is prewired for power only. The junction box for the therm. has 4 wires to thermostat - B, Green, Y, and Gray. These connections match the thermostat. When I hook it all up and turn it on I get nothing. Have I missed something (hopefully simple)? I do have power to junction box and to plug that goes to ac. Directions are straightforward but no troubleshooting. Thanks for any help or suggestions.

[rockwood06]

Originally Posted by jsk

I, with some help, installed a 2nd ducted AC in front bedroom. The AC, therm., and flush mount are all Coleman. Unit is prewired for power only. The junction box for the therm. has 4 wires to thermostat - B, Green, Y, and Gray. These connections match the thermostat. When I hook it all up and turn it on I get nothing. Have I missed something (hopefully simple)? I do have power to junction box and to plug that goes to ac. Directions are straightforward but no troubleshooting. Thanks for any help or suggestions.

You need power to the stat....GREEN In most cases is for FAN,...(Y) may be (YELLOW) and in most cases is for COOLING....YOU NEED A HOT and A COMMON...."B" or GRAY may be one or the other...Just because the wires from both stat and a/c match doesn't mean they work together.

Check to see want the wires stand for from both a/c and stat to make sure they are the right one to connect together.

You need to know from the stat which color is hot and which one is common and the same go's for the a/c unit, once you fine that out connect the two color that need to be connected for hot and common.

[jsk]

Green and gray are fan speeds, yellow is cooling, and blue is -12VDC out of junction box in plenum. This matches what goes to therm.. I have a model 8330 733 ceiling plenum. I am thinking blue powers the therm.. Looking at schematic for junction box now thinking it may have a problem.