Hello,

I have a heater that is only blowing cool ambient air ( it’s cold at current location). Replaced the blower motor due to being toast. And did a radiator fluid change. Burping system was accomplished. Feed and return lines from heater coil are very hot once I run the system on full hot/high fan setting, just no hot air. Several threads in this but older time stamps on them and looking to get a way forward with trouble shooting:
1: flush heater coil and see if buildup is present
2: re-burp the system at a more aggressive incline to get radiator cap above heater coil.
3: any other recommendations for troubleshooting.

note:is was working fine prior to the radiator fluid change.

Thanks

 

Sounds like the air doors are not directing flow through the heater core.

 

That should have been part and parcel of the original burp. The radiator cap should be the highest point in the entire system when burping.

Seems to me that yes, the air doors aren't directing the air properly. I was having trouble getting warm air out of my system. I found that the cable from the temperature selector dial down to the bottom of the heater core containment, wasn't locked into the holder tongs. When the dial was rotated, the cable would move, yes, but the cables outer sheath would just move back and forth, instead of the inner cable moving the air door selector setup. Once I aligned the outer sheath correctly, and locked it down in it's holder ears,it gets hotter than heck.
I don't know your year, or heater set up, but on mine, the whole trouble was where the cable runs into the air door selector device on the bottom, passenger side, right near the central console. Easy to see, just by looking in the passenger side, bottom of the heater core container, passenger side.

My 87's aren't as complex, with no "air door" selectors. Just a lever that selects where the air comes in, and goes into the cabin. For example, the air comes in from outside, goes direct into the cabin. Or to the foot well vents. Like that. My 99 has the air doors, mixing in cold air from outside, or cabin air only, etc etc. Much more complex.

Hood luck, and let us know how things go for ya!
Pat☺

 

All,
Thanks for the inputs. I have found the issue to be the cable running to the door selector not providing enough force to open the valve completely. Should be able to fix it by adding silicone spray to get full motion or shortening the cable.

cheers.

 

Glad youu got it taken care of. Thanks for letting us know what the trouble was.
Pat☺

 

Thanks for the post. I had a more serious problem, coolers stopped working, there was also a problem of fluid leakage in the radiator. I had to replace all parts. It's good that I found jeep jk radiator upgrade, on this site all the details on how to choose a radiator and how to install it correctly