Hey guys,

For whatever reason my heat doesn't work. AC works just fine, fan works with the switch. It won't get hotter than the ambient temperature.

Any ideas? I don't even know what the heater core looks like or where it is really.

Thanks!

Edit: Vehicle is a 2000 Cherokee

 

Try giving the heater core a good flushing.

 

Can be done under the hood pretty easily, yeah?

Thanks!

 

Take the hoses off the core from under the hood (may be a real tight fit to get in there) and blow some air through it. Maybe just plugged.

Also could be a broken blend door or a damaged vacuum tube (I'm pretty sure the door is controlled by vacuum).

 

About to finally revisit this several months later. Just had the radiator blow the tank so I'm wanting to get it all fixed up.

Both of the hoses to/from the heater core were warm when the vehicle warmed up. Same with the radiator. I think the waterpump is good. Radiator and thermostat are brand new.

Once I run air/water through the heater core, and if that doesn't work, how do I go about diagnosing the switch issue? I feel like that may be it since the temp doesn't change regardless of heat/ac and blend position.

What do y'all think?

 

I posted on this in the last month or so; this is what worked for me.

I had flushed the cooling system twice before by using flush kit. It DID NOT help my heat.
So I pulled heater hoses at block. Using mouth, blew through one until no more fluid came out of heater core. Propped both hoses so they were above the heater and poured undiluted Prestone Radiator flush into core until it started to flow from other hose which was just a little above core level. This took about 1/2 bottle. Left it for 30 minutes. Drained core. Repeated. I drained hoses into a milk jug to see what flushed and there was some "junk" but it didn't seem to be a lot. Put hoses back on, filled whole system with 50/50 solution and "burped". Drove until temp gauge was to normal and got better heat but still not great. Went on to highway and got up to speed and heat still better but not great. Kicked into passing gear a couple of times and VOILA, HOT air. Has been great since.