My blower stops in my OLD carrier furnace with the air on. It will work again when I give it a push with my hand. And then lasts a few hours and then its back downstairs for another push. What can I do to fix this. I put a new main board in last year... thanks:)

Try a new motor run capacitor. If that is not it the motor might be defective/going out on overload. When you go down to push it as you say is the motor body hot?

No in fact its cold.

OK then try the capacitor first. Is there 120 volts to the motor when it is supposed to be running and it is not?

Yes

Now I go down and the motor is very hot. Now what? It still works when I push it by hand still. But goes out after a hour or so.

Even though the motors hot it still works until it get to the temp. then it won't start again until I hand start it. I set it at 71 when it got to 71 it shut off and didn't come on until I did it by hand. That took 45 min. the next tim I set it for 68 this time it took a hour and a half before it reached that temp. it shut off and didn't go back on until I did it by hand again. If it was the motor wouldn't it shut off before it reached the disired temp? I think it would run all day if I set it at 60 or something.

Once again, test the run capacitor.

Yes That's For Sure Thanks. I Replaced The Condenser And Its Been Working Fine. Thanks For All The Help.