its heater core and sure you can bypass heater hoses but then you dont have any heat and realy hard to say how its done other than removing a bunch of screws under dash ive worked on cars most of life and i pay to have it done its a pain in the back a good days work if not two might find a how to by typing into search box
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how to by pass heater hose you just remove two ends going into firewall or two heater core and hook them together so coolant flows thru hoses doesnt go into heater core easy fix
