Air Conditioning - Thermostat - 2 wires on 1 terminal

I have a 1993 Tempstar 5000 heating/cooling system, no heat pump. I have the original Honeywell thermostat. I want to replace the thermostat with a programmable thermostat. The Honeywell has five wires, white connected to w; red connected to rc, jumpered to rh; green connected to g; and yellow and blue connected to one y terminal. The old thermostat does not have a "C" terminal. The new programmable thermostat does have a "C" terminal. Is the blue wire connected to the yellow terminal a control wire? Should I hook it up to "C", to "Y" as it is on the old thermostat, or just tape and cap it and don't use it? Thanks for any help.

Edward

If your new stat is battery powered, usually you don't need a common. Connect both the yellow & blue wires to "Y".

Thanks Grady. I'm going to try it now.

Well, its working, but I had a surprise. When I removed the old thermostat, I found that the yellow wire on the y terminal, was not coming from the wall, but was soldered on the back of the thermostat. I hooked the blue wire, which was hooked to the Y terminal in the old thermostat, to the Y terminal on the new thermostat. The heat and air appear to be working. Thanks for your help.

Edward

Glad I could help. Stay cool.