There are two coils on the yoke, one for vertical deflection and the other for horizontal deflection. Take your multimeter, set up to read resistance or ohms, and put it across two slots on the yoke connector. Usually you will measure red to blue and green to the remaining color (I usually see yellow, brown, or white). However, if the colors are different don't sweat it, just copy down the reisistance readings across both pairs. If you are not across a pair then you should not get a reading and you will not damage anything so there is no need to worry about screwing up the yoke taking reisistance readings.