Heater problem on 1997 4.0L
 

i recently bought a 97 4.0 cherokee. The heater hasnt been working. I replaced the thermostat that was not working when i tested it when i took it out. Heater tubing is hot to the touch. I put in new coolant and nothing seems clogged up. A/C works, all the fan speeds work, and everything is clicking over from floor to top to defrost. I also replaced the water pump, and my dad thinks it might be, "airlocked"? I wondered about the blend door. Do you guys have any insight, its getting cold in ohio. I really appropriate any help!

Are ALL the heater tubes hot to the touch? I just had the exact same problem and it ended up being my heatercore hoses being clogged. After a lot of hose water and clr it fixed it right up and my heat feels amazing. Goodluck

Are both heater hoses going to the core hot? Are both upper and lower radiator hoses hot? If all the hoses are hot then you should be getting heat, are you getting any heat at all or is it just warm air? You can try and burp your system, just take the radiator cap off and start the jeep and let it run and watch for air coming out of the filler neck and if you do keep adding anti-freeze until its full. Hope this helps.

gonna try some clr rite now, thanks guys, ill let you know

try back flushing it i had to do it to my 97 cleaned it right out

I'm interested if any of the suggestions worked, cuz I'm having the same issue with my 98 Jeep. Did any suggestions work?

How I fixed my issue
 

So, long story short. I live in Alaska and fixing the heater issues in my jeep was a top priority. Hours on forums and I did everything they recommended to fix this issue to no avail. In order 1) Heater Core 2) Blower Motor 3) Blower Motor Resistor 4)Blend Door Actuator. I was overwhelming frustrated, I spent nearly $1,000 to replace the heater core alone and I was facing another $800 to have the mechanic pull the dash out again and check the blend doors that were possibly stuck in the dash. I had heat coming from the defrost, piss warm heat blowing from the remaining vents that made my grandmother look like the Big Bad Wolf. I spent hours on this forum, youtube videos, mechanic sites, even took it to a mechanic which is why I replaced the blower motor. Still no luck.

Now, I have no idea where I stumbled on it. I think it was an Amazon comment. But someone suggested inspecting the vacuum line. So I pulled out the manual, traced the vacuum line, and eventually found it had snapped right by the reservoir near the front passenger headlight. Of course, they don't make the special tubing anymore so I went to O'Reilly's bought a brake line for $8. Spit on it and spliced it. WALLAH!!!!! Not only was my heater working perfectly but it was blowing strong. So, if anyone reads this and your having issues. Do a vacuum line check before you spend $300 bucks on parts that you may not need.

Hope this helps someone....