We have a Carrier 38TRA048 4 ton AC unit.
This replaced our original "builders" model and has always worked great and is very quiet.

Today, 104 degrees outside, the AC stopped blowing air out of the registers.

The big fan in the Carrier unit outside is blowing and seems to be sucking out the hot air from the house. But no cold air from the registers.

Does this unit somehow use our gas furnace up in the attic? Could it be a blower unit up there that is not coming on?

Please give any info on how these units work together and any advice you can on what I should check out.

I also checked all of our circuit breakers and the electrical outlet where the furnace is plugged in is working fine.

I also replaced the batteries in the Honeywell Chronotherm III thermostat and reprogrammed it just in case.

Any help will be appreciated.

Well, see if the heat blows air out the registers. Not saying it will, but it's worth checking.

Since you mentioned the furnace is in the attic, there is a good chance that someone put a water switch up there that prevents the AC from coming on if the pan under the AC evaporator coil in the attic is full of water.

The drain could be stopped up, the condensate pump not working or it could be a fan problem.