I have a 97 tj that the heat will not get hot. It blows but only cool. My AC was broke all summer due to a busted line and bad compressor. Both are now fixed but system is not charged so I don't have the belt run on it. What will cause the heat not to be warm?
What is your engine temp?
Lift the hood and feel the heater lines. Are both hot? Is one hot and the other rather cold?
Here is a list of items - fixes that could be causing the no heat. All fixes have a thread somewhere on how to with step by step and pics.
Air in the line - Burp the air out
Heater core bypassed - Look to see two lines from engine to firewall near battery exist. If not there is likely a short hose from thermo housing to engine.
Thermo stuck open - replace thermo with correct 195* Thermo
Thermo themo too low temp - replace with thermo with correct 195* thermo
Blocked heater core - interior - remove heater hoses near engine and force water through - garden hose. - in both directions until clear. Might want to flush the entire system is the heater was blocked.
Blocked heater core - exterior - dirt and debris like leaves and mud clogged the fins of the heater core not allowing for heat transfer.
Blend door - 97's have a cable that may have come off the blend door. Or the blend door itself broke on the hinge and needs to be replaced.
Water Pump - Change the water pump- Blades could have rotted off or impeller came loose from the shaft.