[65truckowner]

On my sons 88 k5 the heater is not blowing hot only warm. The coolant is full the engine temp is just under 210. What I dont understand is there is a hose coming from the intake to the heater core then from there to the radiator. The return hose is larger than the intake heater hose. Is this not backwards? But the heater hose coming from the intake has a fitting on it that screws into the intake.I thought the larger hose was the one going into the core not coming out. What else could be causing it to not blow hot. Also the heater core is new.