[4RE KLR]

Joe,
They built your damn house, they know exactly where it is! You are getting the run around. Ask them how fecking many A/C units did they have go out in the last two days.

Screw em, what is wrong with it. I spent over 23 years building homes and I have built many thousands of homes over the years. What is the system doing? I do not know how much you know about the systems but maybe we can get up working even if just temporary till the clowns come.

If the system does not come on at all.
Check the T-stat make sure it is in the right mode.
Check the electric panel and make sure the breaker has not tripped.
Go outside and make sure the breaker is not tripped out by the units.
Check the units for ants around the electrical connections. (spray for them anyway) TURN THE POWER OFF FIRST.
Make sure the freon lines have not been hit by a mower or something else and come loose.
Go to the unit in the attic, take the cover off the front of it and look for a reset button. It should be the size of a small button and will usually be red, but sometimes it will be blue.
Turn off the electricity to the unit, count to ten and then turn it back on.
Make sure the door is installed correctly in the furnace in the attic. If it is off the fan may not come on.
Replace the batteries in the T-stat. I know they may be new but replace them anyway. The batteries may shut down the system. Is it keeping correct time?
Turn the furnace on, just to see if it comes on. Turn it back off. This may take a minute for it to come on. Go check in the attic and see if the furnace actually lights up.
If it is Gas make sure the vent stack is fastened correctly. If not this could cause the system to overheat, even with the A/C and it won't run.

The problem more than likely is either in the T-stat, with ants outside in the connectors or the motherboard in the furnace in the attic. But check everything.

How old is the filter? If the filter is stupid dirty it could cause the system to shut down as a safety measure. There are so many things to check but start here if you have not done this already.

Make sure some neighbor kid has not turned your A/C service "pull breaker" upside down on the box outside by the A/C unit. I have had that happen more than you can imagine. Just open the grey box the power cord is hooked into and pull out the breaker. It will have a handle for you to put your fingers around and pull it out. Yea I know you know to turn off the breakers first right!!!!!!! Make sure the connectors are in the right location. Some of them are even marked UP. Sometime the builders turn these upside down until they system gets ready checked and if you move in and they don't check it, it will not work at all. Basically no power is getting to the compressor, (the outside part)

Let me know what you find, we may be able to get something working, even if it is only temp.