Heat Control Wacky

I have a 1997 Ranger XLT with 2.3 engine. I had a cracked heater control valve that was leaking. Replaced the valve with OEM part but now I can't temper the heat. The hoses are hooked up right and the vacuum valve works properly. vacuum hold valve shut when in off position. I get heat even with the air cond. on. I seemed to have missed something.:confused:

I would watch the control valve why someone changed control panel settings, when you change from heater on, blowing hot, to a/c on blowing cold you should be able to watch the control valve linkage move. if you can not see it move disconnect the vacuum line and see if there is any vacuum present in either setting. I can not remember if the control valve is normally open, or closed, but if it is supposed to be normally open and the vacuum line is disconnected at the other end of the line you would get engine coolant running through the heater core at all times

I can tell you another thing to check. Check the blend air door, they are notorious for breaking and they cause the exact problem that you are describing. The up side to it is that there is a good deal of information on the web about it, and even a makeshift fix that works for some people. The downside is that if it is defective and the makeshift fix won't work, that then you have to pull the entire dash and replace the heater plenum. My 96 does the exact same thing. For an easy test see if the ac works on max ac. If it does get cold then, but not on the other settings, it probably is the blend air door. Good luck.