Hi, Rob. You haven't given us a lot to work with here. So I guess you'll have to do some detective work yourself...
Based on the assumption that you've got a motor with 24VDC armature and
24VDC field, you should get your ohmmeter out (with the motor not connected, of course). By checking for continuity between all the wires, you should find two pairs where there's a fairly low resistance between.(The following advice only applies if that is true.)
Of those two pairs, it's a safe bet the one with the higher resistance is the field. The lower resistance pair should be the armature. Also, if there's no gearing, you should be able to manually turn the motor shaft. You will find that the armature resistance will "blip" as the brushes commute, whereas the field resistance will basically stay the same.
Many times, the armature on DC motors made on this side of the pond will be red (+) and black (-). Euro/Brit motors are more likely to have brown (+) and blue (-) as the armature, but don't bet the farm or the motor on it.
Remember, the field usually gets the fixed voltage, and the armature gets the variable voltage to control motor speed.
Trust, but verify. Start things up with a current-limited power supply and try "bumping" it, providing voltage to armature and field for half a second. That should give you a clue if things are wired correctly.
And by the way, sorry for the sketchy answer. More information usually results in a better response on s.e.b.
Good luck Chris