recently I fixed my AC. Now we have had a fgew cold morning and the heat is nonexistant. It sux. It blows hard so Its not the blower. The AC works great ice cold. I doubt its the switch. I've had this problem before in my wrangler and I searched on here. Found some info. But just ideas no one saying hey thats what the problem was. I am going to have the radiator cap checked, it probably needs to be replaced. I also am famuliar with the heater core flush. Not sure how effective this is. I could check the thermostat. Anything else I should look at? My guess is the thermostat or heater core. Any suggestions? thanks

 

What does your engine temp gauge tell you? Is the engine warming up properly? If it is, run the engine up to temp, crank the heater on high, and feel the hoses. Passenger side hose is the inlet to the heater core, it should be HOT, drivers side is outlet, should be at least warm.....

If those check out, possibility that your funny little servo motor for the temp door crapped out. Do a google search on "heatertreater".

 

I finally tackeled this problem. My radiator needed to be replaced so I replaced the radiator, i also replaced the thermostat while at it. Before replacing the radiator I decided to give the heater core a flush also. Using heater hose and a prestone flush kit I hooked extra heater hose to the heater core hose so I could devert one end into a 5 gallon bucket and the garden hose on the other heater core hose. I then flushed the system in both reverse and forwards. I also flushed it with apple cider vinegar. I then ran water through both again and after added some water I sprayed air with my compressor into the hoses both reverse and forward at 90 psi. I then flushed with more water and then called it good. I did get deposits of black soot. Not alot but some in the very beginning using the garden hose. I got some both in reverse and forward. I then put my new radiator in hooked everything up and ran the system.. Burped it and then the defrosters now worked and the heater works also. Not sure if it was the thermostat or the heatercore. I feel like the core was probably blocked some. But now it works and all is good. If I have any problems I will post back on here with them.

 

Thanks for posting a resolution to your problem (even though it's still hard to say exactly what the main problem was) - a lot of people don't do that, which can be annoying.