Ghostbuster763

My heater core is getting hot but I have no heat coming out the vents. I need some info on how to fix this issue. Also is there a valve to turn on/off the water flow to the core? If so, where is it?

Pelican

Difficult to give advice without knowing year. They are not all the same. Example: most but not all years have a heater control valve in front of the firewall that is actuated by vacuum.

Roler

How you know your heater core is getting hot...got the dash out?...or you mean your heater hoses ?

It's obvious winter is coming for you guys...start of the No Heat thread season..

Ghostbuster763

It is a 1999 cherokee. Yes I did mean the hoses.

kikilink333

I've had 4 xjs like that and the heater core was bad in each. As long as you have the hvac box out you may was well do the AC evaporator. I did not pull the entire dash or take the seats out. If you get the dash loose and pull the passenger side back while keeping the driver side on the steering wheel you can slip the box out the passenger side.

Make sure you check that you hot cold blend door is working. You should hear and feel the air change a little bit when you move it. I think the 97 has a mechanical door control on it so it shouldn't be too hard to feel it moving. The newer years have a little electronic controlled one.

Roler

No valve in your year. older Xj's had them , pre-update.
You sya no heat, but vents are blowing ok otherwise?


If hoses are hot, like upper-radiator-hose-hot and vent blowerspeed is ok, then the next thing would be to check blend door

I think >99 became electronic, so 99 should still be cable-mechanical...

Kalali

Congratulations for being the first to post a no heat thread.... I'm willing to bet it's not going to be the last.... When was the last time you replaced the coolant or did any sort of maintenance in the cooling system?

cruiser54

Blend door most likely.^^ Just as Roler says.

If both heater hoses are the same temp, you have flow through the core.