hey people. i have a 99 jeep cherokee classic. heater blows very little heat. ive checked the coolant its fine and it dose not over heat. any ideas on what the problem could be. everything else works ac, fan everything. but when i turn on the heater theres a little heat when you put your hand to the vent, has enough to some what defrost the windows but im still freezing my *** off..lol thanks for any help guys.

 

It sounds like your heater/water inlet valve is not opening or not opening enough,I would check and see if it is,if not it may have limited or no vacuum to it.

 

check the blend door, they tend to get stuck

 

heater core

 

does it overheat when its warm out?? Mine would overheat only when it was really warm out but took forever to get heat and when it did it was luke warm. Check out the condition of your radiator since its pretty easy anyways

edit: I need to read more carefully.

 

what is a blend door and where is it located? also it dose not overheat at all even when its hot out. heater/water inlet valve where is that located and what dose it look like? im a noob still learning on where things are.

 

Just get a good flush done at a radiator shop. You will be surprized at how much better mine heats after a good flush. I used a home made flush but it did little good but the professional flush got me some serious heat last winter. But then my Jeep is almost 20 years old.

 

Check for vacuum leak - common at intake manifold

 

t-stat?

 

Check ur thermostat. Had the same problem.Didnt noticed the truck was taking longer than usual to warm up.Pulled the stat and found it wouldn't open all the way.Replaced and the heat returned.

 

A Big Thanks to everybody here! This site's saved my butt many times (and kept my wife happy; her cherokee). Flushing the heater core back and forth worked; used some CLR, which seemed to help. Not great heat (never was), but good defrost. I'd already replaced the radiator and thermostat six months prior.