CHEVROLET TRUCK HEATER

I Don't Have Any Heat. Blower Works, Heater Core & Thermostat Replaced And Fuse Inside Truck O.K. What Else Do I Need To Check? 1990...

New Heater Hose Is Clamped On To The Heater Core Tubes And One Of Them Is Leaking. The Coolant Is Coming From Under The Rubber Hose, Coming...