I am installing a motor for a attic fan, the wires on the motor are (blue, brown, and black) the wires at the box are (red, black, white, and a ground) I know the old motor was a two speed and the motor I have now in single, what wires go to what?

If has Temperature controlled, and requires constant power, then connect to th red OR black wire, White to the motor neutral.
Blue can be neutral and brown can be hot.
Need to know what is the black?

Your motor can probably be wired for either 120v or 230v. You should have a wiring diagram tag on the motor you can follow. You probably have a low speed/highspeed switch you are using.You can use either the black or red wire for 120 v power since you are using only one speed. Make sure to cap the unused wire.

Your motor can probably be wired for either 120v or 230v. You should have a wiring diagram tag on the motor you can follow. You probably have a low speed/highspeed switch you are using.You can use either the black or red wire for 120 v power since you are using only one speed. Make sure to cap the unused wire.

The tag only has #'s for the diagram, not colors, the #'s are 11, 27, 20. Both 27 and 20 have a line arrow to them, the 11 line goes through a capacitor and connects to line #27. The only thing I don't understand is what colors (brown, black, blue) goes to the house of red, black, white, and a bare ground. The motor tag says 208-230 volt, could the groung be build into the motor itself it does attach to a grounded fan frame?

Was the old motor strictly for 120v power. If it was and the new motor only says 208-230v on the tag then the new motor will not work for the application. You should get another 2 speed motor. The reason for a black and a red wire plus the white(neutral wire) is that one color controls the lower speed and the other wire controls the higher speed. Either color to neutral should be 120v. What kind of switch do you have controlling the motor?