Evaporator fan will not run.Have replaced fan motor,defrost thermostat and defrost timer.I have power on the yellow wire going to motor but none on the brown wire.Compresor runs and evaporator will freeze. What can I check or replace next? Thanks

Thanks for youre help! I have just got a chance to work on it again today.I guess what had me fooled was every circuit I would test would show continuity so i finally unpluged all connections from terminal block and sprayed them with contact cleaner, put it all back together and it started working.I guess that the circuit was making enough contact to show continuity but would break when the current was applied.I guess you can't always assume anything.Gonna let it run for a couple weeks to see if everything is ok. Thanks again!