1995 Plymouth Voyager luke warm air in front.but hot air bl

Heater problem
1995 Plymouth Voyager 6 cyl Two Wheel Drive

i just changed the heater control valve.
when i went to get it the store had 2 options.
one for the front which had a connection for to water lines.and one for the back which had a connection 3 lines.so i bought the one for the front
and got home and the only control valve i found had 3 hoses.well did the exchange put it on and still only luke warm air from the front vents.where is this other valve located? could not find it.the three hoser is right in front of the heater core on the fire wall.

thanks alot
use to be warm