1996 Toyota Tacoma Repair Question
Toyota Tacoma Heater Problem
We have replaced the thermostat, water pump and check the hoses.
You may not need to replace the heater core. One possibility is to make sure there is no air in the system. you can do this by removing the radiator cap when engine si cool, turn the heater temperature all the way to hot and bring the engine to operating temperature.
I am giving you a walk through duiagnostic for your situation. Just use the link below to get to the diagnostic;
3,292 answers provided