Entry level guidance?
Got some of that as it takes a bit of looking without having to know more than what a radiator hose looks like!
There are times when the AC seems to stop working but the real problem can be that it is working but at the same time as the heater, so you never feel the cool!
If you take a look at the radiator hoses, there is likely to be two that go into the big box under the hood where the parts for the heat and air are hidden. That is one line takes hot water into what looks like a small radiator inside the big cover. The other hose lets the water come back out of the small radiator and on to the rest of the coolant system.
Idea is that when you want heat, you set the controls for heat and it opens a valve along that pair of lines and the blower blows air past the hot water in the small radiator under the dash so that you get warm/hot air inside.
Different systems use different ways to move this valve but one method is vacuum lines that get brittle over time.
This is shaky info, so it needs checked but if you look along those two hoses and find a valve with some method to open and close it, you may want to make sure it moves when you change the controls inside!
Not usually a small tiny thing but has openings in and out for radiator hoses to connect and let water run through?
This is a link to some that Auto Zone sells as examples but there are at least thirty different looking, so just a place to start for what to try to find?
https://www.autozone.com/cooling-he...DIfgp0IMalp3xs6f_T3oNPNFF7xZ2ua0D8rcC5F_3RJbA
If it has vacuum lines going to it, check them for breaks or cracks along the sides.
One test may help? If the valve is open and letting water go through, both in and out will be hot, but if the valve is closed, check for one hose way hotter than the other after the engine has time to get warm?
If it happens to be like the one pictured, you may be able to see the linkage move up and down when controls are changed?
Entry level but maybe also too old to help!! Cheap, though!
