Toyota Repair: Toyota tercel heater, toyota tercel, air doors

Question
I have an '84 Tercel, 3A engine.  The temperature coming out of the heater is no longer hot on the hotest setting and it is difficult to put the  control to the farthest setting COOL or HOT on the control panel. ( There's no air conditioning unit in car.)
I have looked at the manuals at the library, but they are very vague in their instructions on what and how to address this problem. For ex.they say"adjust" the cable, but do not describe how to adjust,etc.

Answer
Hello Susy, welcome to my expert page.
It sounds like there may be a problem with the heater valve, I believe it's located under the hood on the firewall there should be two hoses connected to it and a cable that opens and closes it, try disconnecting the cable and moving the valve lever manually and see if the air temp inside increases and decreases when moved from opened to closed, if it does the valve is good and you need to check the control panel inside the dash and it's cables attached under the left and right side of the center console and make sure they are connected and moving all the air doors, there are no adjustments on these.
If that checks good try replacing the heater valve, or take it off to see if it opens and closes.