My a/c unit @ home will not start. I have checked the following: contactor, capacitor, fan motor, power to the bottom of contactor and the wires coming from thermostat. I got a reading of 6.1 on the thermostat wires. Is my thermostat bad or is there another issue? Thanks.

First of all, model#? Serial#? Heat pump? When you say you checked the voltage on the stat wires, where did you check them at?

6.1 what? If you are talking about 6.1 volts ac ,you are not getting enough power to the contactor,, is the airhandler working when tstat is calling for a/c to work?
Could be your transformer, tstat, or possibly broken stat wire somewhere, check the voltage at the tstat, at the transformer going in and coming out,, where was you checking voltage when you found the 6.1?

6.1 what?? if you are talking about 6.1 volts ac ,you are not getting enough power to the contactor,,,,is the airhandler working when tstat is calling for a/c to work?
could be your transformer,,tstat,,or possibly broken stat wire somewhere,,check the voltage at the tstat,,at the transformer going in and coming out,,,,,where was you checking voltage when you found the 6.1?

Yes it was 6.1 volts. I checked it were they connect to the contactor. The air handler does turn on when I switch the thermostat down to a lower temp. thanks for your reply.