Hey i have a 89 jeep cherokee laredo with the 4.0 engine...the problem is that i change my termostac to a normal temp one.. It had the one the opens when it gets to 180 f' ... My heater was working perfect.. I change the termostac and it stop blowing hot air.. It still turn on and blows air just not hot.. I put the termo the it had and no go... Any sujestion what could the problem be...?????

 

Are your radiator and hoses getting warm? How about the heater hoses? Got an air pocket in there?

 

As Radi said, you have air in the system, most likely. If not, the new thermostat is no good.

 

Yes the hose get hot both of them n on up hills im getting past the mid point in temp never happen before im running a fan always on if i dont turn it on it overheats... How do i get the air out..???

 

When was the last time the heater worked perfect?

 

Carpet wet or smell like antifreeze on the passenger floor?

 

could be the heater core valve vacuum line off.

 

Got it fix .. Dont know the name but it was the valve the has the vacum line inside close to the fire wall.. The one that makes the water circulate... If thats what you where talking about nathanj thanks.. N thanks everybody for your help..

 

you can eliminate that completely. I did.Just bought new hoses and ran it direct. Mine did the same thing.

 

This is the best thing to do! Just get rid of the heater control valve. It's not needed the newer models are never installed.

 

Yup.. Thats what i did... Cut n running direct..