I have a 2002 expo i have no heat in front but i have slight heat in back i have replaced thermostat, flushed heater core and still no heat so i figured blend door is open so instead of tearing out dash i cut the heater box cause the truck is old and ready for junk yard i cut the hole and closed the blend door figuring that would give me heat but no heat it almost feels like the ac is on why wouldnt i get any heat by closing the blend door Both heater hoses are hot to the touch

 

When both heater hoses are the same temp it generally means the core is plugged. Flushing doesn't always clean out accumulated junk and replacement is the only cure.