Washer Warm/Cold setting

Washer will not add hot water to cycle when on Warm/Cold. Have replaced switch and no help. Washer works fine on Hot/Cold cycle. Checked for trash in hot/cold inlets and OK. Is there any way to find a electrical wiring diagram of this machine. I am pretty efficient for checking for electrical problems since that was my chosen field for work.Do not know what controls the valves to get the proper mixture of water for desired settings.
Any and all help appreciated.
Katman