Ever since i changed the shifter handle on automatic

[cr125rider1988]

one cold winter the top of the shifter handle snaped off and was dangling from the metal part of the shifter. The overdrive button still worked until about the summer time, when i made the descision to change it. So i went to a junk yard and got a new one. ever since i changed it the overdrive button has not worked. I have changed the switch, and also checked for any blown fuses and cant find one. I dont really know where to go from here