UM brand new core as mention in my question & of course the antifreeze levels are normal. I guess I'll flush the radiator and replace the heater valve again?
Use a radiator flush to clean out the system ,your system could be blocked up .
A low coolant level could also be the problem
Grit your teeth, and go to the dealer.
I have a 1995 Ford Ranger 2.3 that has NO Heat. I have replaced the heater core, heater valve, thermostat, blend door & actuator, checked all vacuum hoses too. The engine seems to get warm, the indicator does not go up to normal, one hose to the core is cool. It's a nice truck except for this issue. Any clues?
