never post a car with no year, they make changes every year.
1990 to 2002 , ? and is a Toy Corolla in Snake skins(geo)
geo was 90-97/ only. 1.6L or 1.8L?
like heater water valves, or heater damper only heat controls.
so the fan runs at full speed?
the engine gets to 180F and holds?
ok not knowing year, ever see the 2 hose from engine side, to
cab side heater core. the that pass thru? well that is the cab core.
and you get engine hot and touch both hoses. are they both hot
yes, good, if not we work that.
this take like 1 min to do , after engine is hot and works on all cars.
1996 major changes. so?
here is a no year, answer on the controls
when you move each lever, it move a cable (does it) and if does
does the end of each cable move an object.
1: a water valve.
2: a blend door.
the cable has 2 end, either end can fail.
the cable has sheath, just like a bicycle and works the same way.
the sheath is has clamps if broke the cable is rendered useless.
use tie warp to clamp this floating sheath to any near object.
on old cars, i back flush all coolant paths and test the water valve if found. then when all together I have full flow through the heater core.
one guy had mouse nest in core, blocking it.
the system is real simple
hot water must flow thru the heater core. at 180F or more.
and air must flow through the out side of this core and past
all the way through it, and arrive at the vents
if the core is hot, then the flow is bad.
bad damper ,mouse nets. or some pack with leaves.
you now have all you need to fix it.
read this, they mostly bounce off walls but find it.