i have a electronic thermostat [sc2001]and have terminations r,c,w,y,o,b,g, and my central air unit has four wires one is blue,green,white,red where would these go on the new thermostat:confused:

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors. Many have RH and RC to allow seperate transformers for heating and cooling. With just one red wire, jumper them. It may be wired to have the A/C control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan. Digital or programmable thermostats may need the blue wire connected to them.

Your current cable doesn't follow the standard colors. You will have to establish what they are connected to at the other end. You won't use the O, X, etc. unless you have a heat pump. The new thermostat will connect the R terminal to the Y and G when is calls for heat.